Live rock changing colors?

[lorenz0]

So i picked up live rock almost 2 weeks ago and within the first 2 days I started to see white form on it.

Its slowly turning green now.

PH - 8.2
nitrate - 0
nitrite - 0
ammonia - 0.25
gravity - 1.024

I am going to pick up a calcium test tonight and check out where i am at

I read once that this happened to someone as well, turned white and than turned green later but i never found an explaination. To my understanding white in a sw tank = bad