Hi Haroon Rafiq,
Thank you for your question.
Yes, it is possible to customize the appearance of a RadButton while in disabled state, however since the disabled state of our tools is a system setting, you will need to disable the system painting of the disabled state and then re-create the disabled state through themes. In other words, this is not as simple as it sounds.
This is why we created a new KB article describing the proper procedure: Customizing RadButton's disabled state
Feel free to write me if you need further assistance.
All the best,
the Telerik team
Check out Telerik Trainer
, the state of the art learning tool for Telerik products.