I've seen this technique, where you kinda blend the sketch and character into the background before painting the details, and I am curious to try it. Does it help with painting or does it only work if you make the background colours match the character colours.
Well there is indeed the danger of getting the wrong colours. I once used this same technique on a green background, and when I was finished I realised all the colors of the character were very greenish. Usually I start painting on a grey or brown tone, that works best for me, I think. Later on I can add color to the background if I want :-)