That's just a super-cube. Since it's the last layer you're having problems with, I think the only algorithm that you might need is one to rotate that last layer center 180 degrees without affecting the other solved pieces in the last layer. Here is a 2-gen algorithm to do this:
(R U' R' U')5
The 5 means to repeat the algorithm in parentheses 5 times, just in case you were confused about that.
Other than that, I cannot see why you are having problems. If the last layer center needs to be rotated 90 degrees, it' probably because:
1) You have another center rotated 90 degrees in the F2L or
2) You have not solved the corners or edges in the LL.
The corners are the pieces which can really help you see the required color scheme.