1. I would like to draw the individual hairs on a head - rapidly - and have them change from black to different, random shades of black/gray - back and forth - as I draw them. I cannot figure out how to do this. I went to edit brush and fill properties, but I can't figure out how. Any help?

2. Once a brush is made and possibly edited, how can I delete it if I no longer want it listed with that drawing or is that not possible?