Added fixed colors for Synchronizations

plugins/org.yakindu.sct.ui.editor/src/org/yakindu/sct/ui/editor/editor/figures/SynchronizationFigure.java

@@ -10,6 +10,7 @@
  */
 package org.yakindu.sct.ui.editor.editor.figures;
 
+import org.eclipse.draw2d.ColorConstants;
 import org.eclipse.draw2d.RoundedRectangle;
 import org.eclipse.draw2d.geometry.Dimension;
 import org.eclipse.gmf.runtime.draw2d.ui.mapmode.IMapMode;
@@ -28,6 +29,8 @@ public class SynchronizationFigure extends RoundedRectangle {
 	public SynchronizationFigure(IMapMode mapMode) {
 		this.mapMode = mapMode;
 		this.setLineWidth(1);
+		this.setForegroundColor(ColorConstants.black);
+		this.setBackgroundColor(ColorConstants.black);
 		this.setPreferredSize(new Dimension(getMapMode().DPtoLP(defaultSize),
 				getMapMode().DPtoLP(defaultSize)));
 	}