Right now, I would stock up on either Dark Void or Liquid Sunshine, they will be worth alot later on when they go out of cycle.
They are a very hot color and many people like em.
Can also just save your points for when the new cycle comes around and new dyes come out (if they release new dyes this cycle) but if that happens, could get a few of the brand new ones and tax them out for a little more right away.
Liquid Sunshine - 6-10m
Dark Void - 7-11m
Current Atlantic prices.