I have seen so many diffrent eye colors for this character. Do you know which is cannon? I feel like amber/yellow eyes do work with this design. But purple would too.

The majority of designs I've seen of the guy usually feature an amber, and I prefer an Amber purely because it looks good with all the other colors around it; I don't think purple would match up because I don't think there's enough purple or pink in the jungle excluding Plantera's bulbs and the spawned-in Orichalcum, so purple eyes are out of place in my opinion. Excluding all that, don't think there's a canonized eye color for him from what I could find, though.