I tried to give the bill some lines to reflect the structure of an emerald, also some of the feathers have green undertones and slight shape of the structure. It would've been fun if I gave the other colors on the beak structure too so it's like different gems on the beak.

I used colorpencil for the yellows and brown. and markers for the reds and blue. The feathers/ body I colored first with green color pencil and layered it with black marker and colored greens in more so they popped out against the black.