This post is to cover how I paint my pink Chaos Marines...
A couple of examples here - finished a while ago. This is what we are aiming for.
I typically begin with some kind of light spray undercoat - this could be white, a light grey, or a bone colour. It doesn't matter too much which. Dark undercoats would likely need a couple of base coats of the next stage.
The first step is to coat the marine in pink paint - this is Pixie Pink, from the Army Painter Warpaints Fanatic range. Normally I think it down slightlyt with some whater. Most of the fanatic range has very good coverage, but in truth, it doesn't matter 100% that this is an opaque layer (if over light undercoat).
Next, I use a very thinned down wash of GW's Doomfire Magenta contrast paint. This is thinned with contrast medium to somewhere between 10:1 and 5:1 (medium:paint) - the strength tends to be based on how big a batch I am mixing at once.
I'm cheating a bit here - two steps in one photo (shock, horror!). Pretty much everything that isn't going to be pink or bone gets a coat of GW Black Legion contrast. You could use any black really. This is basically to act as a base layer, and the contrast paints are quick to put down. For these models, it means you are covering trim and piping, as well as things like lens, the gun, etc.
The next stage is to paint in the base colour on the bone bits - I tend to use GW's Morghast Bone for this, but you could use your favourite bone starting point.
The next stage is to then paint all the pipework in with Wargames Fanatic Scarab Green.
Next, I have gone over the pink areas with Pixie Pink again, leaving the Doomfire Magenta in the recesses.
And then GW Screaming Skull as an edge highlight to the bone. I've neatened up the end of his weird spine gun with black.
And finally a thin line of GW Fulgrim Pink is used around all the pink armour plates. I've also given the base a coat of GW Warboss Green.
That's it - the model is dione (though this one needs a backpack still - I need to get some more!)