My painted miniatures weren't actually painted by me, but by the people I bought them from.
The U.N.E. troops are the most detailed, with a US Marines paint-scheme of black with red trim and occasional edge-flames; the visors are blue with highlights. Weapons are generally done in metallic dry-brushing over black, silver for the main areas, and gold for ammo and other details. The original owner also went through the trouble of adding a custom shoulder badge with a US flag on it, individual trooper names, and rank chevrons. I'm really not that fond of the paint scheme as a whole, but I have to say that it was very well done.
The same owner also painted a number of my Fantasian troops, and for those s/he opted for a dark "Soviet" green, with red star shoulder patches and weapon details. Weapons are otherwise done in more-or-less standard metallic dry-brushing over blacks.
My Machines are the most complete, and the forces that are painted are all done with metallic dry-brushing (mostly silver, with a few others) over black, with occasional bright, subtly-shaded colours for highlight areas (one shoulder of Mk I Assault Fiend, G3A Disruptor Swords, G1C Nega-sphere Generator barrels, etc.). Simple, but looks great on the table.
Neither my Black Empire nor my Infranites have received a lick of paint yet, but I've been meaning to get around to it for a couple months now. I've been toying with the idea of contracting the painting of the Black Empire stuff out, as I don't think I can do the miniatures justice, but I think I'm going to do the Infranites myself, probably with the dip method. I was thinking of ranging from deep reds to much brighter orangey-brown with them.