diff --git a/htroot/SearchEventPicture.java b/htroot/SearchEventPicture.java
index 57780624d..ba8f44098 100644
--- a/htroot/SearchEventPicture.java
+++ b/htroot/SearchEventPicture.java
@@ -41,7 +41,7 @@ public class SearchEventPicture {
         final String eventID = header.get("event", SearchEventCache.lastEventID);
         if (eventID == null) return null;
         final RasterPlotter yp = NetworkGraph.getSearchEventPicture(sb.peers, eventID, 0);
-        if (yp == null) return new RasterPlotter(1, 1, RasterPlotter.MODE_SUB, "000000"); // empty image
+        if (yp == null) return new RasterPlotter(1, 1, RasterPlotter.DrawMode.MODE_SUB, "000000"); // empty image
         
         return yp;
     }
diff --git a/htroot/WatchWebStructure_p.html b/htroot/WatchWebStructure_p.html
index 83524bc90..077f64083 100644
--- a/htroot/WatchWebStructure_p.html
+++ b/htroot/WatchWebStructure_p.html
@@ -7,10 +7,10 @@
 <style type="text/css">
   #left {
     float: left;
-    width: 224px;
+    width: 246px;
   }
   form dt {
-    width: 40px;
+    width: 70px;
   }
   form dd {
     width: 130px;
@@ -44,24 +44,29 @@ To see a list of all APIs, please visit the <a href="http://www.yacy-websuche.de
 	</dd>
 	<dt>depth</dt>
 	<dd>
-	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depthd]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[time]#"><img src="env/grafics/minus.gif" width="11" height="11" alt="minus"/></a>
+	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depthd]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[time]#&amp;colortext=#[colortext]#&amp;colorback=#[colorback]#&amp;colordot=#[colordot]#&amp;colorline=#[colorline]#&amp;colorlineend=#[colorlineend]#"><img src="env/grafics/minus.gif" width="11" height="11" alt="minus"/></a>
 	  <input type="text" name="depth" value="#[depth]#" size="1" maxlength="1" />
-      <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depthi]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[time]#"><img src="env/grafics/plus.gif" width="11" height="11" alt="plus" /></a>
+      <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depthi]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[time]#&amp;colortext=#[colortext]#&amp;colorback=#[colorback]#&amp;colordot=#[colordot]#&amp;colorline=#[colorline]#&amp;colorlineend=#[colorlineend]#"><img src="env/grafics/plus.gif" width="11" height="11" alt="plus" /></a>
 	</dd>
 	<dt>nodes</dt>
 	<dd>
-	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodesd]#&amp;time=#[time]#"><img src="env/grafics/minus.gif" width="11" height="11" alt="minus"/></a>
+	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodesd]#&amp;time=#[time]#&amp;colortext=#[colortext]#&amp;colorback=#[colorback]#&amp;colordot=#[colordot]#&amp;colorline=#[colorline]#&amp;colorlineend=#[colorlineend]#"><img src="env/grafics/minus.gif" width="11" height="11" alt="minus"/></a>
 	  <input type="text" name="nodes" value="#[nodes]#" size="4" maxlength="4" />
-	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodesi]#&amp;time=#[time]#"><img src="env/grafics/plus.gif" width="11" height="11" alt="plus"/></a>
+	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodesi]#&amp;time=#[time]#&amp;colortext=#[colortext]#&amp;colorback=#[colorback]#&amp;colordot=#[colordot]#&amp;colorline=#[colorline]#&amp;colorlineend=#[colorlineend]#"><img src="env/grafics/plus.gif" width="11" height="11" alt="plus"/></a>
 	</dd>
     <dt>time</dt>
 	<dd>
-	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[timed]#"><img src="env/grafics/minus.gif" width="11" height="11" alt="minus"/></a>
+	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[timed]#&amp;colortext=#[colortext]#&amp;colorback=#[colorback]#&amp;colordot=#[colordot]#&amp;colorline=#[colorline]#&amp;colorlineend=#[colorlineend]#"><img src="env/grafics/minus.gif" width="11" height="11" alt="minus"/></a>
 	  <input type="text" name="time" value="#[time]#" size="4" maxlength="4" />
-	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[timei]#"><img src="env/grafics/plus.gif" width="11" height="11" alt="plus"/></a>
+	  <a href="WatchWebStructure_p.html?host=#[host]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[timei]#&amp;colortext=#[colortext]#&amp;colorback=#[colorback]#&amp;colordot=#[colordot]#&amp;colorline=#[colorline]#&amp;colorlineend=#[colorlineend]#"><img src="env/grafics/plus.gif" width="11" height="11" alt="plus"/></a>
 	</dd>
     <dt>size</dt>
 	<dd><input type="text" name="width" value="#[width]#" size="5" maxlength="5" />&nbsp;x&nbsp;<input type="text" name="height" value="#[height]#" size="5" maxlength="5" /></dd>
+    <dt>Background</dt><dd>Color <input type="text" name="colorback" value="#[colorback]#" size="6" maxlength="6" /></dd>
+    <dt>Text</dt><dd>Color <input type="text" name="colortext" value="#[colortext]#" size="6" maxlength="6" /></dd>
+    <dt>Line</dt><dd>Color <input type="text" name="colorline" value="#[colorline]#" size="6" maxlength="6" /></dd>
+    <dt>Dot</dt><dd>Color <input type="text" name="colordot" value="#[colordot]#" size="6" maxlength="6" /></dd>
+    <dt>Dot-end</dt><dd>Color <input type="text" name="colorlineend" value="#[colorlineend]#" size="6" maxlength="6" /></dd>
     <dt>&nbsp;</dt>
     <dd><input type="submit" value="change" /></dd>
   </dl>
@@ -69,7 +74,7 @@ To see a list of all APIs, please visit the <a href="http://www.yacy-websuche.de
 </form>
 </div><br />
 
-<img align="right" src="WebStructurePicture_p.png?host=#[besthost]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[time]#" alt="WebStructurePicture"/>
+<img align="right" src="WebStructurePicture_p.png?host=#[besthost]#&amp;depth=#[depth]#&amp;width=#[width]#&amp;height=#[height]#&amp;nodes=#[nodes]#&amp;time=#[time]#&amp;colortext=#[colortext]#&amp;colorback=#[colorback]#&amp;colordot=#[colordot]#&amp;colorline=#[colorline]#&amp;colorlineend=#[colorlineend]#" alt="WebStructurePicture"/>
 
 #%env/templates/footer.template%# 
 </body>
diff --git a/htroot/WatchWebStructure_p.java b/htroot/WatchWebStructure_p.java
index 68a6cbf69..5988f6106 100644
--- a/htroot/WatchWebStructure_p.java
+++ b/htroot/WatchWebStructure_p.java
@@ -18,6 +18,12 @@ public class WatchWebStructure_p {
     public static serverObjects respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
         final Switchboard sb = (Switchboard) env;
         final serverObjects prop = new serverObjects();
+
+        String color_text    = "888888";
+        String color_back    = "FFFFFF";
+        String color_dot     = "11BB11";
+        String color_line    = "222222";
+        String color_lineend = "333333";
         
         int width = 768;
         int height = 576;
@@ -28,12 +34,17 @@ public class WatchWebStructure_p {
         String besthost;
         
         if (post != null) {
-            width = post.getInt("width", 768);
-            height = post.getInt("height", 576);
-            depth = post.getInt("depth", 3);
-            nodes = post.getInt("nodes", width * height * 100 / 768 / 576);
-            time = post.getInt("time", -1);
-            host = post.get("host", "auto");
+            width         = post.getInt("width", 768);
+            height        = post.getInt("height", 576);
+            depth         = post.getInt("depth", 3);
+            nodes         = post.getInt("nodes", width * height * 100 / 768 / 576);
+            time          = post.getInt("time", -1);
+            host          = post.get("host", "auto");
+            color_text    = post.get("colortext",    color_text);
+            color_back    = post.get("colorback",    color_back);
+            color_dot     = post.get("colordot",     color_dot);
+            color_line    = post.get("colorline",    color_line);
+            color_lineend = post.get("colorlineend", color_lineend);
         }
         
         if (host.equals("auto")) {
@@ -76,7 +87,12 @@ public class WatchWebStructure_p {
         prop.put("timed", (time < 0) ? 9000 : Math.max(1000, time - 1000));
         prop.put("width", width);
         prop.put("height", height);
-        
+
+        prop.put("colortext",    color_text);
+        prop.put("colorback",    color_back);
+        prop.put("colordot",     color_dot);
+        prop.put("colorline",    color_line);
+        prop.put("colorlineend", color_lineend);
         return prop;
     }
 }
diff --git a/htroot/WebStructurePicture_p.java b/htroot/WebStructurePicture_p.java
index c052e958d..6c80c8952 100644
--- a/htroot/WebStructurePicture_p.java
+++ b/htroot/WebStructurePicture_p.java
@@ -51,6 +51,12 @@ public class WebStructurePicture_p {
     public static RasterPlotter respond(final RequestHeader header, final serverObjects post, final serverSwitch env) {
         final Switchboard sb = (Switchboard) env;
         
+        String color_text    = "888888";
+        String color_back    = "FFFFFF";
+        String color_dot     = "11BB11";
+        String color_line    = "222222";
+        String color_lineend = "333333";
+        
         int width = 768;
         int height = 576;
         int depth = 3;
@@ -59,12 +65,17 @@ public class WebStructurePicture_p {
         String host = null;
         
         if (post != null) {
-            width = post.getInt("width", 768);
-            height = post.getInt("height", 576);
-            depth = post.getInt("depth", 3);
-            nodes = post.getInt("nodes", width * height * 100 / 768 / 576);
-            time = post.getInt("time", -1);
-            host = post.get("host", null);
+            width         = post.getInt("width", 768);
+            height        = post.getInt("height", 576);
+            depth         = post.getInt("depth", 3);
+            nodes         = post.getInt("nodes", width * height * 100 / 768 / 576);
+            time          = post.getInt("time", -1);
+            host          = post.get("host", null);
+            color_text    = post.get("colortext",    color_text);
+            color_back    = post.get("colorback",    color_back);
+            color_dot     = post.get("colordot",     color_dot);
+            color_line    = post.get("colorline",    color_line);
+            color_lineend = post.get("colorlineend", color_lineend);
         }
         
         // too small values lead to an error, too big to huge CPU/memory consumption, resulting in possible DOS.
@@ -86,7 +97,7 @@ public class WebStructurePicture_p {
         RasterPlotter graphPicture;
         if (host == null) {
             // probably no information available
-            graphPicture = new RasterPlotter(width, height, RasterPlotter.MODE_SUB, GraphPlotter.color_back);
+            graphPicture = new RasterPlotter(width, height, RasterPlotter.DrawMode.MODE_SUB, color_back);
             PrintTool.print(graphPicture, width / 2, height / 2, 0, "NO WEB STRUCTURE DATA AVAILABLE.", 0);
             PrintTool.print(graphPicture, width / 2, height / 2 + 16, 0, "START A WEB CRAWL TO OBTAIN STRUCTURE DATA.", 0);
         } else {
@@ -102,10 +113,10 @@ public class WebStructurePicture_p {
             if (host != null) place(graph, sb.webStructure, hash, host, nodes, timeout, 0.0, 0.0, 0, depth);
             //graph.print();
             
-            graphPicture = graph.draw(width, height, 40, 40, 16, 16);
+            graphPicture = graph.draw(width, height, 40, 40, 16, 16, color_back, color_dot, color_line, color_lineend, color_text);
         }
         // print headline
-        graphPicture.setColor(GraphPlotter.color_text);
+        graphPicture.setColor(color_text);
         PrintTool.print(graphPicture, 2, 8, 0, "YACY WEB-STRUCTURE ANALYSIS", -1);
         if (host != null) PrintTool.print(graphPicture, 2, 16, 0, "LINK ENVIRONMENT OF DOMAIN " + host.toUpperCase(), -1);
         PrintTool.print(graphPicture, width - 2, 8, 0, "SNAPSHOT FROM " + new Date().toString().toUpperCase(), 1);
diff --git a/htroot/imagetest.java b/htroot/imagetest.java
index 3797a7c5e..8385a7e9d 100644
--- a/htroot/imagetest.java
+++ b/htroot/imagetest.java
@@ -64,7 +64,7 @@ public class imagetest {
         for (int i = 20; i < 100; i++) r.setPixel(i, 34, new int[]{0, 0, 255});
         return bi;
         */
-        final RasterPlotter img = new RasterPlotter(800, 600, RasterPlotter.MODE_SUB, "FFFFFF");
+        final RasterPlotter img = new RasterPlotter(800, 600, RasterPlotter.DrawMode.MODE_SUB, "FFFFFF");
         img.setColor(RasterPlotter.GREY);
         for (int y = 0; y < 600; y = y + 50) PrintTool.print(img, 0, 6 + y, 0, Integer.toString(y), -1);
         for (int x = 0; x < 800; x = x + 50) PrintTool.print(img, x, 6    , 0, Integer.toString(x), -1);
diff --git a/source/de/anomic/yacy/graphics/NetworkGraph.java b/source/de/anomic/yacy/graphics/NetworkGraph.java
index 1d82416e1..fbb0666c8 100644
--- a/source/de/anomic/yacy/graphics/NetworkGraph.java
+++ b/source/de/anomic/yacy/graphics/NetworkGraph.java
@@ -171,7 +171,7 @@ public class NetworkGraph {
 
     private static RasterPlotter drawNetworkPicture(final yacySeedDB seedDB, final int width, final int height, final int passiveLimit, final int potentialLimit, final int maxCount, final int coronaangle, final long communicationTimeout, final String networkName, final String networkTitle, final String bgcolor) {
 
-        RasterPlotter networkPicture = new RasterPlotter(width, height, (bgcolor.equals("000000")) ? RasterPlotter.MODE_ADD : RasterPlotter.MODE_SUB, bgcolor);
+        RasterPlotter networkPicture = new RasterPlotter(width, height, (bgcolor.equals("000000")) ? RasterPlotter.DrawMode.MODE_ADD : RasterPlotter.DrawMode.MODE_SUB, bgcolor);
         if (seedDB == null) return networkPicture; // no other peers known
         
         final int innerradius = Math.min(width, height) / 5;
@@ -404,7 +404,7 @@ public class NetworkGraph {
 
         final int exprlength = 19;
         logo = newLogo;
-        bannerPicture = new RasterPlotter(width, height, RasterPlotter.MODE_REPLACE, bgcolor);
+        bannerPicture = new RasterPlotter(width, height, RasterPlotter.DrawMode.MODE_REPLACE, bgcolor);
 
         // draw description
         bannerPicture.setColor(textcolor);
@@ -423,7 +423,7 @@ public class NetworkGraph {
         if (logo != null) {
             final int x = (100/2 - logo.getWidth()/2);
             final int y = (height/2 - logo.getHeight()/2);
-            bannerPicture.insertBitmap(logo, x, y, 0, 0, RasterPlotter.FILTER_ANTIALIASING);
+            bannerPicture.insertBitmap(logo, x, y, 0, 0, RasterPlotter.FilterMode.FILTER_ANTIALIASING);
         }
 
         if (!bordercolor.equals("")) {
diff --git a/source/de/anomic/yacy/graphics/OSMTile.java b/source/de/anomic/yacy/graphics/OSMTile.java
index 0fc316103..f14450feb 100644
--- a/source/de/anomic/yacy/graphics/OSMTile.java
+++ b/source/de/anomic/yacy/graphics/OSMTile.java
@@ -61,7 +61,7 @@ public class OSMTile {
         width = w * 2 + 1;
         final int h = (height - 1) / 2;
         height = h * 2 + 1;
-        final RasterPlotter m = new RasterPlotter(256 * width, 256 * height, RasterPlotter.MODE_REPLACE, "FFFFFF");
+        final RasterPlotter m = new RasterPlotter(256 * width, 256 * height, RasterPlotter.DrawMode.MODE_REPLACE, "FFFFFF");
         List<Place> tileLoader = new ArrayList<Place>();
         Place place;
         // start tile loading concurrently
diff --git a/source/net/yacy/visualization/AnimGifEncoder.java b/source/net/yacy/visualization/AnimGifEncoder.java
index f5b8ca30e..46b6ba44c 100644
--- a/source/net/yacy/visualization/AnimGifEncoder.java
+++ b/source/net/yacy/visualization/AnimGifEncoder.java
@@ -1139,7 +1139,7 @@ public class AnimGifEncoder {
     public static void main(final String[] args) {
         System.setProperty("java.awt.headless", "true");
         
-        final RasterPlotter m = new RasterPlotter(200, 300, RasterPlotter.MODE_SUB, "FFFFFF");
+        final RasterPlotter m = new RasterPlotter(200, 300, RasterPlotter.DrawMode.MODE_SUB, "FFFFFF");
         RasterPlotter.demoPaint(m);
         final File file = new File("/Users/admin/Desktop/testimage.gif");
         
diff --git a/source/net/yacy/visualization/Captcha.java b/source/net/yacy/visualization/Captcha.java
index cb115ba39..d2bfb19cc 100644
--- a/source/net/yacy/visualization/Captcha.java
+++ b/source/net/yacy/visualization/Captcha.java
@@ -32,7 +32,7 @@ import net.yacy.kelondro.logging.Log;
 
 public class Captcha extends RasterPlotter {
 
-    public Captcha(final int width, final int height, final byte displayMode, final String code) {
+    public Captcha(final int width, final int height, final DrawMode displayMode, final String code) {
         super(width, height, displayMode, "FFFFFF");
         this.create(code);
     }
@@ -85,7 +85,7 @@ public class Captcha extends RasterPlotter {
         // go into headless awt mode
         System.setProperty("java.awt.headless", "true");
 
-        final Captcha m = new Captcha(200, 70, RasterPlotter.MODE_REPLACE, args[1]);
+        final Captcha m = new Captcha(200, 70, RasterPlotter.DrawMode.MODE_REPLACE, args[1]);
         try {
             ImageIO.write(m.getImage(), "png", new java.io.File(args[0]));
         } catch (final java.io.IOException e) {
diff --git a/source/net/yacy/visualization/ChartPlotter.java b/source/net/yacy/visualization/ChartPlotter.java
index b08ad7e6b..4fa1ddd6c 100644
--- a/source/net/yacy/visualization/ChartPlotter.java
+++ b/source/net/yacy/visualization/ChartPlotter.java
@@ -53,7 +53,7 @@ public class ChartPlotter extends RasterPlotter {
     public ChartPlotter(final int width, final int height, final String backgroundColor, final String foregroundColor, final String lightColor,
                       final int leftborder, final int rightborder, final int topborder, final int bottomborder,
                       final String name, final String subline) {
-        super(width, height, RasterPlotter.MODE_REPLACE, backgroundColor);
+        super(width, height, RasterPlotter.DrawMode.MODE_REPLACE, backgroundColor);
         this.leftborder = leftborder;
         this.rightborder = rightborder;
         this.topborder = topborder;
diff --git a/source/net/yacy/visualization/DemoApplet.java b/source/net/yacy/visualization/DemoApplet.java
index 9a81672ab..f65cb9ae3 100644
--- a/source/net/yacy/visualization/DemoApplet.java
+++ b/source/net/yacy/visualization/DemoApplet.java
@@ -48,7 +48,7 @@ public class DemoApplet extends Applet implements Runnable {
 
     public void update(final Graphics g) {
         final Dimension d = getSize();
-        offGraphics = new RasterPlotter(d.width, d.height, RasterPlotter.MODE_REPLACE, "FFFFFF");
+        offGraphics = new RasterPlotter(d.width, d.height, RasterPlotter.DrawMode.MODE_REPLACE, "FFFFFF");
         paintFrame(offGraphics);
         g.drawImage(offGraphics.getImage(), 0, 0, null);
     }
diff --git a/source/net/yacy/visualization/GraphPlotter.java b/source/net/yacy/visualization/GraphPlotter.java
index e06f7918e..7e909288a 100644
--- a/source/net/yacy/visualization/GraphPlotter.java
+++ b/source/net/yacy/visualization/GraphPlotter.java
@@ -43,13 +43,6 @@ public class GraphPlotter {
 
     // a ymageGraph is a set of points and borders between the points
     // to reference the points, they must all have a nickname
-
-    public  static final long color_back = 0xFFFFFF;
-    public  static final long color_text = 0x888888;
-    private static final long color_dot = 0x11BB11;
-    private static final long color_line = 0x222222;
-    private static final long color_lineend = 0x333333;
-    
     
     HashMap<String, coordinate> points;
     HashSet<String> borders;
@@ -132,8 +125,23 @@ public class GraphPlotter {
         }
     }
     
-    public RasterPlotter draw(final int width, final int height, final int leftborder, final int rightborder, final int topborder, final int bottomborder) {
-        final RasterPlotter image = new RasterPlotter(width, height, RasterPlotter.MODE_SUB, color_back);
+    public RasterPlotter draw(
+            final int width,
+            final int height,
+            final int leftborder,
+            final int rightborder,
+            final int topborder,
+            final int bottomborder,
+            final String color_back,
+            final String color_dot,
+            final String color_line,
+            final String color_lineend,
+            final String color_text
+            ) {
+        RasterPlotter.DrawMode drawMode = RasterPlotter.DrawMode.MODE_SUB;
+        if (RasterPlotter.darkColor(color_back)) drawMode = RasterPlotter.DrawMode.MODE_ADD;
+        
+        final RasterPlotter image = new RasterPlotter(width, height, drawMode, color_back);
         final double xfactor = ((rightmost - leftmost) == 0.0) ? 0.0 : (width - leftborder - rightborder) / (rightmost - leftmost);
         final double yfactor = ((topmost - bottommost) == 0.0) ? 0.0 : (height - topborder - bottomborder) / (topmost - bottommost);
         
@@ -154,7 +162,7 @@ public class GraphPlotter {
             image.setColor(color_text);
             PrintTool.print(image, x, y + 10, 0, name.toUpperCase(), 0);
         }
-        
+
         // draw lines
         final Iterator<String> j = borders.iterator();
         coordinate[] border;
diff --git a/source/net/yacy/visualization/RasterPlotter.java b/source/net/yacy/visualization/RasterPlotter.java
index 91616dd2c..a1160f437 100644
--- a/source/net/yacy/visualization/RasterPlotter.java
+++ b/source/net/yacy/visualization/RasterPlotter.java
@@ -57,13 +57,13 @@ public class RasterPlotter {
     public static final long BLUE   = 0x0000FF;
     public static final long GREY   = 0x888888;
     
-    public static final byte MODE_REPLACE = 0;
-    public static final byte MODE_ADD = 1;
-    public static final byte MODE_SUB = 2;
+    public static enum DrawMode {
+        MODE_REPLACE, MODE_ADD, MODE_SUB;
+    }
     
-    public static final byte FILTER_ANTIALIASING = 0;
-    public static final byte FILTER_BLUR = 1;
-    public static final byte FILTER_INVERT = 2;
+    public static enum FilterMode {
+        FILTER_ANTIALIASING, FILTER_BLUR, FILTER_INVERT;
+    }
     
     protected final int            width, height;
     private final   int[]          cc;
@@ -71,13 +71,13 @@ public class RasterPlotter {
     private final   WritableRaster grid;
     private         int            defaultColR, defaultColG, defaultColB;
     private final   long           backgroundCol;
-    private final   byte           defaultMode;
+    private         DrawMode       defaultMode;
     
-    public RasterPlotter(final int width, final int height, final byte drawMode, final String backgroundColor) {
+    public RasterPlotter(final int width, final int height, final DrawMode drawMode, final String backgroundColor) {
         this(width, height, drawMode, Long.parseLong(backgroundColor, 16));
     }
     
-    public RasterPlotter(final int width, final int height, final byte drawMode, final long backgroundColor) {
+    public RasterPlotter(final int width, final int height, final DrawMode drawMode, final long backgroundColor) {
         if (!(MemoryControl.request(1024 * 1024 + 3 * width * height, false))) throw new RuntimeException("ymage: not enough memory (" + MemoryControl.available() + ") available");
         this.cc = new int[3];
         this.width = width;
@@ -119,6 +119,10 @@ public class RasterPlotter {
         */
     }
     
+    public void setDrawMode(DrawMode drawMode) {
+        this.defaultMode = drawMode;
+    }
+    
     public BufferedImage getImage() {
         return this.image;
     }
@@ -131,8 +135,19 @@ public class RasterPlotter {
         return height;
     }
     
+    public static boolean darkColor(final String s) {
+        return darkColor(Long.parseLong(s, 16));
+    }
+    
+    public static boolean darkColor(final long c) {
+        final int r = (int) (c >> 16);
+        final int g = (int) ((c >> 8) & 0xff);
+        final int b = (int) (c & 0xff);
+        return r + g + b < 384;
+    }
+    
     public void setColor(final long c) {
-    	if (this.defaultMode == MODE_SUB) {
+    	if (this.defaultMode == DrawMode.MODE_SUB) {
     		final int r = (int) (c >> 16);
             final int g = (int) ((c >> 8) & 0xff);
             final int b = (int) (c & 0xff);
@@ -159,7 +174,7 @@ public class RasterPlotter {
         if ((x < 0) || (x >= width)) return;
         if ((y < 0) || (y >= height)) return;
         synchronized (cc) {
-        	if (this.defaultMode == MODE_REPLACE) {
+        	if (this.defaultMode == DrawMode.MODE_REPLACE) {
         		if (intensity == 100) {
         			cc[0] = defaultColR;
             		cc[1] = defaultColG;
@@ -172,7 +187,7 @@ public class RasterPlotter {
         			c[2] = (intensity * defaultColB + (100 - intensity) * c[2]) / 100;
                     grid.setPixel(x, y, c);
         		}
-        	} else if (this.defaultMode == MODE_ADD) {
+        	} else if (this.defaultMode == DrawMode.MODE_ADD) {
         		int[] c = grid.getPixel(x, y, cc);
         		if (intensity == 100) {
         			c[0] = (0xff & c[0]) + defaultColR; if (cc[0] > 255) cc[0] = 255;
@@ -184,7 +199,7 @@ public class RasterPlotter {
         			c[2] = (0xff & c[2]) + (intensity * defaultColB / 100); if (cc[2] > 255) cc[2] = 255;
         		}
                 grid.setPixel(x, y, c);
-        	} else if (this.defaultMode == MODE_SUB) {
+        	} else if (this.defaultMode == DrawMode.MODE_SUB) {
         		int[] c = grid.getPixel(x, y, cc);
         		if (intensity == 100) {
         			c[0] = (0xff & c[0]) - defaultColR; if (cc[0] < 0) cc[0] = 0;
@@ -240,6 +255,10 @@ public class RasterPlotter {
         }
     }
     
+    public void lineDot(final int x0, final int y0, final int x1, final int y1, final int radius, final int distance, final String lineColor, final String dotColor) {
+        lineDot(x0, y0, x1, y1, radius, distance, Long.parseLong(lineColor, 16), Long.parseLong(dotColor, 16));
+    }
+    
     public void lineDot(final int x0, final int y0, final int x1, final int y1, final int radius, final int distance, final long lineColor, final long dotColor) {
         // draw a line with a dot at the end.
         // the radius value is the radius of the dot
@@ -337,7 +356,7 @@ public class RasterPlotter {
      * @param filter chooses filter 
      * @author Marc Nause
      */
-    public void insertBitmap(final BufferedImage bitmap, final int x, final int y, final byte filter) {
+    public void insertBitmap(final BufferedImage bitmap, final int x, final int y, final FilterMode filter) {
         insertBitmap(bitmap, x, y, -1, filter);
     }    
     
@@ -366,7 +385,7 @@ public class RasterPlotter {
      * @param filter chooses filter 
      * @author Marc Nause
      */
-    public void insertBitmap(final BufferedImage bitmap, final int x, final int y, final int xx, final int yy, final byte filter) {
+    public void insertBitmap(final BufferedImage bitmap, final int x, final int y, final int xx, final int yy, final FilterMode filter) {
         insertBitmap(bitmap, x, y, bitmap.getRGB(xx, yy), filter);
     }        
     
@@ -409,13 +428,13 @@ public class RasterPlotter {
      * @param filter chooses filter 
      * @author Marc Nause
      */
-    public void insertBitmap(final BufferedImage bitmap, final int x, final int y, final int transRGB, final byte filter) {
+    public void insertBitmap(final BufferedImage bitmap, final int x, final int y, final int transRGB, final FilterMode filter) {
         insertBitmap(bitmap, x, y, transRGB);
 
         final int bitmapWidth = bitmap.getWidth();
         final int bitmapHeight = bitmap.getHeight();        
         
-        if (filter == FILTER_ANTIALIASING) {
+        if (filter == FilterMode.FILTER_ANTIALIASING) {
             
             int transX = -1;
             int transY = -1;
@@ -463,7 +482,7 @@ public class RasterPlotter {
      * @author Marc Nause
      */
     public void antialiasing(final int lox, final int loy, final int rux, final int ruy, final int bgcolor) {
-        filter(lox, loy, rux, ruy, FILTER_ANTIALIASING, bgcolor);
+        filter(lox, loy, rux, ruy, FilterMode.FILTER_ANTIALIASING, bgcolor);
     }
 
     /**
@@ -475,7 +494,7 @@ public class RasterPlotter {
      * @author Marc Nause
      */
     public void blur(final int lox, final int loy, final int rux, final int ruy) {
-        filter(lox, loy, rux, ruy, FILTER_BLUR, -1);
+        filter(lox, loy, rux, ruy, FilterMode.FILTER_BLUR, -1);
     }
 
     /**
@@ -487,7 +506,7 @@ public class RasterPlotter {
      * @author Marc Nause
      */
     public void invert(final int lox, final int loy, final int rux, final int ruy) {
-        filter(lox, loy, rux, ruy, FILTER_INVERT, -1);
+        filter(lox, loy, rux, ruy, FilterMode.FILTER_INVERT, -1);
     }
     
     /**
@@ -499,7 +518,7 @@ public class RasterPlotter {
      * @param filter chooses filter 
      * @author Marc Nause
      */
-    private void filter(int lox, int loy, int rux, int ruy, final byte filter, final int bgcolor) {
+    private void filter(int lox, int loy, int rux, int ruy, final FilterMode filter, final int bgcolor) {
 
         // taking care that all values are legal
         if (lox < 0) { lox = 0; }
@@ -539,7 +558,7 @@ public class RasterPlotter {
                 rgbG = 0;
                 rgbB = 0;  
                 
-                if (filter == FILTER_ANTIALIASING || filter == FILTER_BLUR) {
+                if (filter == FilterMode.FILTER_ANTIALIASING || filter == FilterMode.FILTER_BLUR) {
                     // taking samples from neighbours of pixel
                     if (i > lox) {
                         rgb = image.getRGB(i - 1, j);
@@ -589,7 +608,7 @@ public class RasterPlotter {
                 // add value of pixel
                 // in case filter is used for antialiasing this will only be done if
                 // the pixel is on the edge to the background color
-                if ((filter == FILTER_ANTIALIASING && border) || (filter == FILTER_BLUR)) {
+                if (filter == FilterMode.FILTER_ANTIALIASING && border || filter == FilterMode.FILTER_BLUR) {
                     rgbR += (rgb >> 16 & 0xff);
                     rgbG += (rgb >> 8 & 0xff);
                     rgbB += (rgb & 0xff);
@@ -597,14 +616,14 @@ public class RasterPlotter {
                     border = false;
                 } 
                 // set to value of pixel => keep value
-                else if (filter == FILTER_ANTIALIASING) {
+                else if (filter == FilterMode.FILTER_ANTIALIASING) {
                     rgbR = (rgb >> 16 & 0xff);
                     rgbG = (rgb >> 8 & 0xff);
                     rgbB = (rgb & 0xff);
                     numberOfNeighbours = 1;
                 }
                 // set value of pixel to inverted value (using XOR)
-                else if (filter == FILTER_INVERT) {
+                else if (filter == FilterMode.FILTER_INVERT) {
                     rgb = rgb ^ 0xffffff;
                     rgbR = (rgb >> 16 & 0xff);
                     rgbG = (rgb >> 8 & 0xff);
@@ -736,7 +755,7 @@ public class RasterPlotter {
         // go into headless awt mode
         System.setProperty("java.awt.headless", "true");
         
-        final RasterPlotter m = new RasterPlotter(200, 300, MODE_SUB, "FFFFFF");
+        final RasterPlotter m = new RasterPlotter(200, 300, DrawMode.MODE_SUB, "FFFFFF");
         demoPaint(m);
         final File file = new File("/Users/admin/Desktop/testimage.png");
         try {