I have tested this code with our latest version and it was working correctly. Still, you can try the following snippet too:
Just to make sure we are allowed to set the BackColor, we will set the DrawFill too.
If this does not help, please get back to me with a sample app, where the undesired behavior can be reproduced and I will gladly look into it.
Regards,
Stefan
Telerik
Check out the Telerik Platform - the only platform that combines a rich set of UI tools with powerful cloud services to develop web, hybrid and native mobile apps.