One of the problems I've come across when painting my Dark Eldar is choice of colour for the army. Generally Dark Eldar are painted in blues and purples to produce a cohesive uniform colour scheme. This has never really interested me as I think that the 'fluff' associated with the Dark Eldar (a piratical raiding party, formed over time) would not give them a uniform colour scheme. I decided that to reinforce the idea that the army had formed over time from individuals and small groups gathering together I would paint them all different colours. Unfortunately this means that I have to think up approximately 40 different colour schemes. My solution to this was to turn to a book I own called 'Colour Management' which is a guide for graphic designers on the use of colour.
It's a fantastic resource, simply open the book at any page, choose a poster or logo design and pick out the main colours. These kind on books can be picked up relatively cheaply from discount book stores, they don't have to be specifically graphic design books, any book of modern art, posters or corporate logos will be useful.
I've started three miniatures so far this way and I'm pretty happy with the results. Right, better get them finished and get on with the rest...