I just noticed that 1 or 2 of my cories (I have 6) seem to have orange faces. It is hard to see because they seem to hiding most of the time. The Cory's that I normally see out and about feeding look normal. What could this be?
What kind of corys are they? Do you have a picture that you could post?
As a general rule, when anything seems unusual about a cory, do a water change. It won't hurt and will often do a lot of good. Do you know the ammonia, nitrite and nitrate readings of your water?