I think most people would said that in mature adult fish, Percula orange is brighter, black is darker, and white is whiter. Almost all Ocellaris have this dirty orange that fade from lighter at the bottom of the fish to darker on top. No clear border between black and orange.Yeah I personal prefer ocellaris over percula ten fold. I like the clean orange with white stripes outlined by black much better than the black fading that is on percula. I also think that perculas orange is less bright and vibrant and more dull.
But, just my 0.02
On Percula, almost all the time there is a clear border from black to orange with darker orange.
These day it is not hard to get bright orange in your clowns by feeding them color enhance food.