Bug 230218 [JFace] Test failures in PresentationsTestSuite and RCP Tests
bundles/org.eclipse.jface/src/org/eclipse/jface/resource/ColorRegistry.java
while (iterator.hasNext()) {
            Object next = iterator.next();
            ((Color) next).dispose();
        }
    }
    /**
     * Returns the <code>color</code> associated with the given symbolic color 
     * name, or <code>null</code> if no such definition exists.
     * 
     * @param symbolicName symbolic color name
     * @return the <code>Color</code> or <code>null</code>
     */
    public Color get(String symbolicName) {
        Assert.isNotNull(symbolicName);
        Object result = stringToColor.get(symbolicName);
        if (result != null) {
			return (Color) result;
		}
        Color color = null;
        result = stringToRGB.get(symbolicName);
        if (result == null) {
			return null;
		}
        color = createColor((RGB) result);
        stringToColor.put(symbolicName, color);
        return color;
    }
    /* (non-Javadoc)
     * @see org.eclipse.jface.resource.ResourceRegistry#getKeySet()
     */