Bug 184423 [JFace] ColorRegistry.getRGB(String) can return null
I20070427-0010 ColorRegistry.getRGB(String) can return null but this is not speced in the Javadoc.
bundles/org.eclipse.jface/src/org/eclipse/jface/resource/ColorRegistry.java
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.eclipse.core.runtime.Assert;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.swt.widgets.Display;
/**
 * A color registry maintains a mapping between symbolic color names and SWT 
 * <code>Color</code>s.
 * <p>
 * A color registry owns all of the <code>Color</code> objects registered with 
 * it, and automatically disposes of them when the SWT Display that creates the 
 * <code>Color</code>s is disposed. Because of this, clients do not need to 
 * (indeed, must not attempt to) dispose of <code>Color</code> objects 
 * themselves.
 * </p>
 * <p>
 * Methods are provided for registering listeners that will be kept
 * apprised of changes to list of registed colors.
 * </p>
 * <p>
 * Clients may instantiate this class (it was not designed to be subclassed).
 * </p>
 * 
 * @since 3.0
 */
public class ColorRegistry extends ResourceRegistry {