Cracking project.
As the red your using on your chaos Warriors is slightly transparent. There's a really simple old school look/method that'll make them pop..If you paint all the armour black then add a blotch pattern of gold over it .( just let the gold do what it normally does and separate out slightly with a first coat. )The apply a slightly thinned coat of your red over the top of the whole thing You get a lovely multi tonal chaos Red armour.
I think I've still got an old Space Crusade dreadnought done with this technique. If it's of interest I could take a picture of it.
Mark