drools-eclipse/org.drools.eclipse/src/main/java/org/drools/eclipse/editors/DRLSourceViewerConfig.java
public IPresentationReconciler getPresentationReconciler(ISourceViewer sourceViewer) {
        PresentationReconciler reconciler = new PresentationReconciler();

        //bucket partition... (everything else outside a rule)
        DefaultDamagerRepairer dr = new DefaultDamagerRepairer(getScanner());
        reconciler.setDamager(dr, IDocument.DEFAULT_CONTENT_TYPE);
        reconciler.setRepairer(dr, IDocument.DEFAULT_CONTENT_TYPE);

        //inside a rule partition
        dr = new DefaultDamagerRepairer(getScanner());
        reconciler.setDamager(dr, DRLPartionScanner.RULE_PART_CONTENT);
        reconciler.setRepairer(dr, DRLPartionScanner.RULE_PART_CONTENT);

        //finally, inside a multi line comment.
        dr = new DefaultDamagerRepairer(new SingleTokenScanner(
                new TextAttribute(ColorManager.getInstance().getColor(
                        ColorManager.SINGLE_LINE_COMMENT))));
        reconciler.setDamager(dr, DRLPartionScanner.RULE_COMMENT);
        reconciler.setRepairer(dr, DRLPartionScanner.RULE_COMMENT);

        return reconciler;
    }
public IPresentationReconciler getPresentationReconciler(ISourceViewer sourceViewer) {
        PresentationReconciler reconciler = new PresentationReconciler();

        //bucket partition... (everything else outside a rule)
        DefaultDamagerRepairer dr = new DefaultDamagerRepairer(getScanner());
        reconciler.setDamager(dr, IDocument.DEFAULT_CONTENT_TYPE);
        reconciler.setRepairer(dr, IDocument.DEFAULT_CONTENT_TYPE);

        //inside a rule partition
        dr = new DefaultDamagerRepairer(getScanner());
        reconciler.setDamager(dr, DRLPartionScanner.RULE_PART_CONTENT);
        reconciler.setRepairer(dr, DRLPartionScanner.RULE_PART_CONTENT);

        //finally, inside a multi line comment.
        dr = new DefaultDamagerRepairer(new SingleTokenScanner(
                new TextAttribute(ColorManager.getInstance().getColor(
                        ColorManager.SINGLE_LINE_COMMENT))));
        reconciler.setDamager(dr, DRLPartionScanner.RULE_COMMENT);
        reconciler.setRepairer(dr, DRLPartionScanner.RULE_COMMENT);

        return reconciler;
    }
Define reconciler - this has to be done for each partition.
Currently there are 3 partitions, Inside rule, outside rule and inside comment.