<ajaxToolkit:ColorPickerExtender runat="server" ID="ColorPickerExtender1" TargetControlID="Color1" OnClientColorSelectionChanged="colorChanged" /> The following JavaScript function is called in response to the OnClientColorSelectionChanged event:function colorChanged(sender) { sender.get_element().style.color = "#" + sender.get_selectedColor(); } <ajaxToolkit:ColorPickerExtender runat="server" TargetControlID="Color2" PopupButtonID="Image1" SampleControlID="Sample1" SelectedColor="33ffcc" />