Bug 13507 LinkedPositionUI has a reference to SWT.COLOR_RED
LinkedPositionUI(ITextViewer, LinkedPositionManager) - org.eclipse.jdt.internal.ui.text.link.LinkedPositionUI has a reference to SWT.COLOR_RED which will be unreadble if the user sets their background colour to Red. We will be adding a getErrorText colour to JFaceColours in build >20020411. You may want to use that.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/link/LinkedPositionUI.java
Position position= fManager.getPreviousPosition(fFramePosition.getOffset());
		if (position == null) {
			fViewer.getTextWidget().getDisplay().beep();
		} else {
			fFramePosition= position;
			selectRegion();
			redrawRegion();
		}				
	}
	/*
	 * @see VerifyKeyListener#verifyKey(VerifyEvent)
	 */
	public void verifyKey(VerifyEvent event) {
		switch (event.character) {
		
		case 0x09:
			{
				Point selection= fViewer.getTextWidget().getSelection();
				IRegion region= fViewer.getVisibleRegion();
				int offset= selection.x + region.getOffset();
				int length= selection.y - selection.x;
				
				
				if (!LinkedPositionManager.includes(fFramePosition, offset, length)) {
					leave(UNINSTALL | COMMIT | UPDATE_CARET);
					return;
				}
			}