Just discovered this nifty little
set of plugins . They're handy for speeding up your flat colouring. Basically it picks out enclosed areas in your line art and fills them all in with random colours. The default settings generally put decent contrast between adjacent areas, so you can just go in with the paint bucket & magic wand tools and make stuff the correct colour. It's mostly just a visual thing so you can better see where you need to lay down your flat colours, but I've used it for my last couple of strips and its shaved a bit off of total production time.
Make sure you've got a copy of your uncoloured line art on a separate layer, then run the multifill plugin (it's in the filters menu) on the background layer it'll colour it in all psychadelic-like) then run the 'flatten' plugin (again in the filters menu), which will expand the colours and get rid of most of the lines on that layer, then it's wand and bucket time
