Remember what Klasse actually is. It is a non abrasive chemical paint cleaner. It does it's job with chemical action, so to speak, instead of abrading the surface. It may have a slight cut to it but very, very slight. With that said, I never use anything more aggessive than a white pad. In most cases I use a black polishing pad if I am not doing any correction afterwards. I think an orange will leave behind too much marring that you will have to address afterwards.
So, if I am placing a Klasse application into a two or three step process, I could go with white. If I am doing a paint cleansing, seal/wax, then I stick with the black pad to minimize any marring.