Are you planning on converting them in any way to make them more obviously Chaos tainted? Or going more of the pure-fluff route?
I would definitely look at going much darker than the image you've posted. That almost pinkish red is a bit too bright; personally I like my Eldar much darker, and if they were going to be Chaosish, darker still.
On my Fire Dragons I used a combination of pre-shading in greyscale followed by the Citadel glaze - Bloodletter, followed by a coat of Carroburg Crimson to darken things up. Doing all this over a black base coat gives a dark bloody red. I actually used the same technique for this Carnifex -
Maybe something like that, with a gloss coated almost black red helmet, with a sickly green contrast for the spirit stones? Would give them a dark, bloody look...
For vehicles, maybe go a predominantly black/deep red colour (again achieveable with the colours above, with the addition of some other reds like Wazdakka or Khorne) with some brighter (but not too bright) panels for highlights?
Unless you want to go all Emperor's Children Crazy Pink up in there...
Personally I think dark colours with small areas of bright highlight "work" better on the battlefield - the army looks cohesive, and characters and individuals stand out. I think this is especially true for Eldar. They are actually, I think, the
WH40k race with the darkest history. Mankind is all gritty and Gears of Warish but the Eldar are fighting both *for* survival and *against* their own natures. All of humanities enemies come from without; the Eldar fight those within. Altansar is not so much lost as just losing that fight a little bit more than the others...