The initial sketch was done in pencil. I scanned it, gave it a bit of an outline and touch-up with the brush tool in Paint Tool SAI, then used my favorite textured brush for the shading. I didn't really plan ahead with the colors, just chose some and played around with them till I was happy with the effect.
The colours evoke a sort of pastel-coloured-painting feeling. It's nice!
The only drawback, if you can call it that, is those crystal patterns on her legs, they seem flat-coloured, which seems a little off when you consider the way shading stands out all over the rest of the work.