Bug 278479 [CSS] SWT unit tests failing "This isn't an RGBColor type"
tests/org.eclipse.e4.ui.tests.css.swt/src/org/eclipse/e4/ui/tests/css/swt/ButtonTest.java
static final RGB RED = new RGB(255, 0, 0);
	static final RGB GREEN = new RGB(0, 255, 0);
	static final RGB BLUE = new RGB(0, 0, 255);
	CSSEngine engine;	
	
	protected Button createTestButton(String styleSheet) {
		Display display = Display.getDefault();
		engine = createEngine(styleSheet, display);
		
		
		Shell shell = new Shell(display, SWT.SHELL_TRIM);
		FillLayout layout = new FillLayout();
		shell.setLayout(layout);
		Composite panel = new Composite(shell, SWT.NONE);
		panel.setLayout(new FillLayout());
		Button buttonToTest = new Button(panel, SWT.CHECK);
		buttonToTest.setText("Some button text");
		
		engine.applyStyles(shell, true);
		shell.pack();