It does not look sick, and it is not an acropora. That is a pocillopora species. The white tips on it are normal for branching SPS like that, it just means they are growing. When other spots start to turn white, or all of the branches begin to bleach, then you know something is wrong. The coral in that picture looks great actually. Nice polyp extension.
I was thinking the same thing, maybe it is browned out, but i have seen a couple po species that were brown, or at least looked brown so i wasn't too sure. Maybe it has color? Just the pictures throw it off?