I wonder if there is any kind of inteligent bucket tool that detects the color of the outline in the surface and then fills that surface using the next color on the same ramp that the outline is using. Is that possible at the moment? If no, that would be a interesting feature for the bucket tool. I like to create my arts firstly by single outlines and then filling the surfaces and I know more people that does the same, so I believe a filling tool that can deal with selective outline like that would be greatly appreciated.