Hi Andrew Currie,
Actually, this is the way to set custom transparency to the modal overlay of RadWindow, as this is the only selector that controls that particular element.
However, I am starting to think that you need the window itself
semi transparent - is it so? If this is your requirement, the selector you need to set to semi-transparent is .RadWindow
, not the overlay element:
If you are not sure how to achieve this, send me a sample page along with exact description of what your requirements are and which one you need to set to semi-transparent - the window or the overlay and I will do this for you.
the Telerik team