Thank you guys!
@Colour Of War:
for the joints i only used washes over a white base. so first seraphim sepia then casandora yellow and finally bloodletter glaze. simple but effective. ;P
and for the carapace i used a black undercoat. then first mephiston red mixed with a little black, after that only mephiston red, after that 50/50 mephiston/evil suns scarlet. and last a highlight with only evil suns scarlet.