Oh, nice idea mixing the smooth Vallejo silver metals with inks to get gold. Wish I would have thought of that. I just finished a few minis trying to paint gold trim with new GW metallic golds and those were like painting with sludge. Cheers Doc!
The more diluted the paint, the quicker it dries (at least I know this is true for acrylic and oil paints) and when you're layering highly diluted acrylic paint you want the previous layers to be pretty dry otherwise you're going to tear up the paint that's already on the mini. So by the time you see him switching colors, the previous layer is already dry.
Great job! I was wondering how you primered the Bones mini? I have heard that certain primers don't work well with the white Reaper soft plastic. No idea on the the new Black Bones as far as primer goes.
There's actually a list of rattle can primers that will work well with the Bones resin on the Reaper forums. Since I have an airbrush, I just use Vallejo Polyurethane Surface Primer; I know that Badger Stynylrez works as well.