You’re very much welcome, my friend! Any time!
Well, that same thing has been bothering me for a long time. Because, all of his skins (Minecraft skins, that is) seem to have blue eyes, but most fan art, even the ones done by the Artists in The Yogscast, seem to portray him with brown eyes. I have tried to get a close enough and clear picture of him in real life, to see if this is true, but annoyingly I have yet to succeed. So, I’m sorry to say that I do not know, friend. But, I don’t believe you’ll get any comments saying that you’ve coloured his eyes wrong, because many before you have used brown, too! But, thank you for considering me to answer this question, and for trusting my answer! I hope to some day give you a proper one!
I’ll be sure to let you know if I end up finding out!