Which version of our RadControls for WPF you are currently using? I've tried the same code against the RadColorPicker control and as you can see in this video
, it works as expected. Please upgrade to latest version of the RadControls and try the same code again.
If you continue to have difficulty, local reproduction is necessary. Please share your app with us by attaching it to a new support ticket which would be confidential, or I could share a Dropbox link with you. If you cannot share the full app, perhaps your developers can create a small demo app for us that exhibits the same behavior.
the Telerik team