Bug 12329 [Cell Editors] Request:ComboBoxCellEditor READ_ONLY style
Although CCombo accepts SWT.READ_ONLY style, there is no way to specify style when it is used in ComboBoxCellEditor. How about adding createControl(Composite parent, int style) method to ComboBoxCellEditor class?
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ColorCellEditor.java
* Method declared on DialogCellEditor.
 */
protected Object openDialogBox(Control cellEditorWindow) {
	ColorDialog dialog = new ColorDialog(cellEditorWindow.getShell());
	Object value = getValue();
	if (value != null)
		dialog.setRGB((RGB) value);
	value = dialog.open();
	return dialog.getRGB();
}
/* (non-Javadoc)
 * Method declared on DialogCellEditor.
 */
protected void updateContents(Object value) {
	RGB rgb = (RGB) value;
	
	if (rgb == null) {
		rgb = new RGB(0, 0, 0);
	}
	
	if (image != null)
		image.dispose();
	ImageData id = createColorImage(colorLabel.getParent().getParent(), rgb);
	ImageData mask = id.getTransparencyMask();
	image = new Image(colorLabel.getDisplay(), id, mask);
	colorLabel.setImage(image);
	rgbLabel.setText("(" + rgb.red + "," + rgb.green + "," + rgb.blue + ")");
}
}