DIY colouring components I find silver, black and occasionally red are quite dull colour choices. Granted there are some components out there in more interesting colours, but the engineer in me won't let me choose the "wrong" component simply because it looks pretty.

So I'm wondering what the options are for colouring metallic components, chainring bolts, brake levers, etc, at home. I suspect painting wouldn't look quite right and in the case of bolts, might cause things to get stuck or flake off in use.

How about anodysing? Is it something that can be done safely at home without too much risk of ruining the component? Does anyone have experience of this?
There are  Powder-Coating kits that are made for home use. They are available in the U.S. from Sears-Craftsman, The Eastwood Company and others. They range in price from under $200 to as much as you want to spend. The process involves using the supplied gun to apply a colored dry powder to the part. The part is then baked in a household oven. The baking cures the powder to something similar in appearance to a ceramic glaze. It is a very durable finish. It does create some issues though. It cannot be touched up if damaged. The coating is thicker than paint. Threaded holes and close tolerence mating surfaces must be protected during the process. Of course you could only color components that can have all their plastic parts removed.