I decided on a purple colour scheme for my Kabal because I'd never really used that colour on any of my other armies before. I went for
Basecoat: 50:50 chaos black/lych purple
Edge highlight: lych purple
Edge highlight: warlock purple
High spots: tentacle pink
I wanted a contrasting spot colour, so I went for light blue on the hair and drug dispenser.
When it came to adding wych cult units to the force I experimented with reversing the colour scheme, so that I was painting blue wych suits and pink hair, which also looked pretty good.
I'm now at the point of painting the transports for my cult units and I'm not sure whether to paint them the same as my other Kabal vehicles (as if the wyches a hitching a ride with the Kabal) or keep the theme of reversed colours (the wyches bring their own ride) and go for a blue raider with pink sails which will stand out from my other vehicles.
Any thoughts? I'll look into getting some pics up sometime this week
Edit: really sorry, this should have gone in the painting forum, that'll teach me to have multiple windows open at once...