I realise it needs this, and the only problem is the user interface, getting it to do a real time preview with a background gradient is a lot harder, although I think I can with quite a bit of effort.
For the moment, you have a choice, either no real time preview of backgrounds but the ability to do gradients (not individual colours though), or wait a bit longer and have proper realtime preview, as you do with the foreground text.
btw. if anyone knows how to set the background colour of an individual character in a rich text control let me know