I actually think Nick's eyes are both brown and he slips in a blue contact. There was an episode about a 1 or 2 back and during the confessional he absolutely two (2) brown eyes. Look, I find the guy a total poser and an angry one at that. I dont find him very talented or personable and think every single performance has sounded the same. But I do know it is more likely a person with brown eyes - pops in a blue contact to look different, vs a blue eyed person popping in a brown contact. Ah... a creative poser needing to "stand out" but a poser all the same.