Well, I'm a big fan of bright, stand-out colors, so I personally don't have a problem with that aspect of the show. But I do miss the level of detail that went into secondary characters back in the first three seasons.
Nowadays, somesecondary characters seem to be hastily thrown together and just seem to lack that level of polish that the original seasons had.
I'm not complaining, though, because this is still my favorite cartoon on television, and I love new episodes.