Can some of you help with a couple of good field marks to separate S. flaveola from S. luteola, S. raimondii and S. olivascens?

If I see one (at least in Lima) I always imagine it's S. flaveola and the red face is my main physical characteristic to look for, but I know the they have brownish and greenish feather and that makes them too similar to the other.

Any help?

Rodrigo