Should be fine, I've topped it with OCW on black paint a few times. On anything other than solid black though, I'm really happy with how OS looks on its own.
Here's one. This was a few months ago at a car show. OS/Souveran, washed, then spit shined with Souveran. It was the best I think this car have ever looked. The car also had an exterior detail a couple of days before by Joe @ Word of Mouth detailing (cool guy btw).
My car now has 3 layers of Optiseal on it. I washed it last night with ONR. Then I applied some JW- CJ. It looked really really good. I might have to stick with this combo. Ease of use is pretty awesome with both O/S and CJ. Here's a couple of pics.