I saw this almost as soon as you posted, and didn't want to reply without having at least some minor crit to bring to the table. A truly stunning piece, phenomenal colour choice, excellent metallic effect... you get where I'm heading. Pure love.
Two very minor crits, one of which is the nose, and Godslayer already mentioned that. The other is more of a concern than a crit, really, and it involves your choice of purple as a near dark. Given your obvious understanding of colour, I'll assume it was an intentional aesthetic choice, but after some minor playing, I found that, for me, a dark teal helps maintain more of a bronzy look.
In all seriousness, though, you know a helluva lot more about colour than me, so I wouldn't take this suggestion too seriously.