private void ExtendChoices()
        {
            List <string> lchoices = new List <string>(choices);

            if (useFlags.HasFlag(ColorList.StaticFlags.allowUndefined))
            {
                unselectedText = StringTable.GetString("ColorDef.Undefined");
                // this name should not be a name of a defined color. But if it is so, we prefix the text by "-" as often as necessary
                while (colorList.Find(unselectedText) != null)
                {
                    unselectedText = "-" + unselectedText + "-";
                }
                lchoices.Insert(0, unselectedText);
            }
            //if (useFlags.HasFlag(ColorList.StaticFlags.allowFromParent))
            //{
            //    lchoices.Add(ColorDef.CDfromParent.Name);
            //}
            //if (useFlags.HasFlag(ColorList.StaticFlags.allowFromStyle))
            //{
            //    lchoices.Add(ColorDef.CDfromStyle.Name);
            //}
            choices = lchoices.ToArray();
        }