I don't think apps need to be updated, the OS will just send two separate screen redraws to the app. If you put a window half on an 8-bit color screen and half

I don't think apps need to be updated, the OS will just send two separate screen redraws to the app. If you put a window half on an 8-bit color screen and half on a 16-bit color screen it works fine too, I don't see why this would be different.