Bug 55256 [Colors/Fonts] Rollback change to ColorRegistry for gets() on colors that do not exist
bundles/org.eclipse.jface/src/org/eclipse/jface/resource/ColorRegistry.java
*/
	public ColorRegistry(Display display) {
		Assert.isNotNull(display);
		this.display = display;
		hookDisplayDispose();
	}
	
	/**
	 * Create a new <code>Color</code> on the receivers <code>Display</code>.
	 * 
	 * @param symbolicName the symbolic color name.
	 * @param rgb the <code>RGB</code> data for the color.
	 * @return the new <code>Color</code> object.
	 */
	private Color createColor(String symbolicName, RGB rgb) {
		return new Color(display, rgb);
	}
	/**
	 * Returns the default color (SWT.COLOR_WIDGET_BACKGROUND).
	 */
    Color defaultColor() {
		if (display == null) {
			Shell shell = new Shell();
			Color color = new Color(null, shell.getBackground().getRGB());
			shell.dispose();
			return color;
		} else
			return new Color(
			        display, 
			        display