Looks just a little bright for my tastes, but may just be the lighting. The overall scheme is somewhat reminiscent of a poisonous insect or something without being the standard black/yellow, which I like.
And I like the idea of swapping colours between your Cult and Kabal units - I was planning on doing the same with mine (but different colours), to retain the unified appearance of an army while distinguishing different unit types. I've not got as far as painting any Wyches yet though. Do you have a Kabalite warrior for comparison?