I've always done comics in color ever since I transitioned to digital art— due to the way I work, it's actually easier than black & white. And besides, I just have way too much fun playing with colors. ^^ It's therapeutic, almost. I can't imagine taking on a long-term project without any color...
I've been learning and studying lots about color over the past few years; it's been my main area of improvement.
My current pet project is learning to create "atmosphere"...making a scene feel green or blue or whatever, but not just by making the scene monochromatic.
It's really hard...I know most digital artists would just use blend mode layers, but they usually don't work out well for me...and even when they do, if they don't turn out 100% right I never know how to tweak them to perfection. So I figure I'll just do the best thing for myself and learn the technique from scratch.
I do most of my color-picking experiments in my comics:
I think my most successful recent experiment, however, was with a group of character designs:
When I looked back at it the next day, for a second I thought something was wrong with my screen; all the colors were so consistently cool-tinted. Even now, the illusion persists a little...I think that's a good sign. :9
I can't wait until I finally get this, and can freely move on to the next color challenge. 'Cause there's always another one...colors, man...