I don't know if it's counted as art in it's own right, but I'm trying to colour lineart at a professional level. (I'm not there yet)
I'll show you guys things I've done, and update this as I do more.
These are the two I've been using as samples:


This is one I did yesterday:

It was hard because feathers and fur are new to me, and they're all complicated and detailed. I'm not happy with how it turned out, but the girl I'm doing it for was impressed, so I guess thats what counts maybe...
This is one I did today:

and here's a screencap of a WIP: