I've given GW's new contrast paints a try. For my Warhammer Fantasy RPG campaign, a couple of my players don't come from a miniatures background, so I picked up a couple cheap resin minis from Reaper Miniatures, primed them, and speed painted them in a couple hours using contrast paint.
From left to right:
Viktor the Witch Hunter, Karl the Priest of Sigmar, and Aeseric the Aelf
Primed with flat gray primer.
Viktor's cloak is Gryph-charger Gray with a touch of Cygor Brown. His tunic is Aggaros Dunes. Skin is Fyreslayer Flesh, boots are Cygor Brown. My store didn't have any metallic contrast paint on hand, so I did the metal parts the old way. The studded leather is Aggaros Dunes with Ironbreaker Gray (watered down) layered on top, blades are Administratum Gray with Ironbreaker Gray layered on top, then washed with Nuln Oil
Karl's cloak is Aggaros Dunes with the upper parts layered with Nazdreg yellow for the faded look. Flesh is Fyreslayer Flesh. Tunic is Cygor Brown, boots are Cygor Brown with Ork Flesh on top. Karl's Dagger is Administratum Gray with Ironbreaker on top and Nuln Oil wash.
Aeseric's Cloak is Cygor Brown. His hair is Nazdreg Yellow and his flesh is Fyreslayer flesh with a small amount of Cygor Brown mixed in. His tunic, armor, personal effects, etc, are Militarum Green, and his staff is Leviadon Blue.
Overall, I still need to get a feel for how these paints work, and try them when I have more time to appreciate them. For cranking out a few models in 2 hours, though, they were quite nice and easy to use. My players who aren't into the hobby were pleased that they had minis to match the other players who also play wh40k, so there's a happy ending to this story.