In the current version of RadControls it is not possible to control the gradient of the RadHtmlChart. However, I have logged your idea in our feedback portal here
, so that you can monitor, comment or vote on it. If it gets enough votes and approval from our management you can expect it to be implemented in the future.
I have also updated your Telerik points as a small token of gratitude for sharing your ideas with us.
the Telerik team
If you want to get updates on new releases, tips and tricks and sneak peeks at our product labs directly from the developers working on the RadControls for ASP.NET AJAX, subscribe to their blog feed