Right...
I've always said that black wheels looks good on Saxo's if the side and front bump/strips are left black. Because yours are colour coded, I think the wheels shouldn't go black. If you look at Leckie's car, that is how it should be done (with the silver/black theme).
The white wheels... That does look nice. Even with smoked front and rear lights, I think the white wheels can still be pulled off.
In my opinion, I don't think you should go dark but stick to a lighter colour wheel.
Up to you at the of the day mate.