I just add multiply or overlay coloured layers on top of the greyscale layers I already have... It worked really well with this piece but for some pieces it doesn't work as well. I find it a lot easier sometimes just doing the entire image in greyscale and then adding colour layers on top and fixing things up that way... It's much easier when you have the correct tones
yeah they do... I tried doing this with other pieces but it just didn't work out as well... but for whatever reason it was really easy with this one... I think it really depends on whether or not you can nail the tonal values of each colour in black and white