Hi Martin Hoey,
The RadColorPicker control does not offer the functionality you need out of the box. In case you were using a RadColorPicker with ShowIcon=true, you could have used the approach demonstrated in our Shared colors collection between different ColorPickers with ShowIcon set to "true" knowledge base article
In your case however, you use a RadColorPicker that creates its HTML on the server and does not keep its items collection in its client state. For your particular case (RadColorPicker with items that you define yourself in the Items collection, ShowEmptyColor="false", PreviewColor="false", Preset="None" and PaletteModes="WebPalette"), you can use the following approach:
- First you need to pass the information about the colors in the Items collection of your source RadColorPicker in some form to the client - you can use a HiddenField for that.
- When you filter the colors from the source RadColorPicker, you should first detach some of the handlers that the second RadColorPicker has attached, dispose its HTML and then recreate it with the new items collection. You need not do all this yourself - you can use some of the internal methods of the RadColorPicker for this.
I have attached a simple test page that demonstrates how you can get the colors from one RadColorPicker, filter them and then set the result collection as items for the second RadColorPicker.
Please note that this approach uses internal methods of the RadColorPicker and tries to "trick" the control so it might have side effects and in case your RadColorPicker configuration is different than the above described one, it might not work.
the Telerik team