What lizard did I see at Lowry Park Zoo? (Thinking it was a skink of some sort.)?

I saw a lizard at Lowry Park Zoo. It was almost like a rainbow color but that could have been a prism effect from the water fall it was under. Speaking of which, about half the enclosure was water and the lizard seemed to be enjoying it. He was a large lizard (a little smaller than a green iguana). I've seen pictures of skinks and its head shape and scales resembled one. I don't remember what the label on the enclosure said and it's driving me crazy. If you could help me with its identification I'd really appreciate it. Thanks :)