People have been asking me how I colour things, lately. Aaand I fail at saving enough to make a proper walkthrough. So, uh. Here's this. I use Photoshop CS. My technique pretty much consists of overlay/multiply layers using yellow/purple respectively (or similar colours, depending on atmosphere) with low-opacity airbrushes to create highlights and shadows, then painting over those layers with mid-opacity hard round brushes.

View the finished image here: http://www.furaffinity.net/view/5927556