Flame Angel

[chris#1]

Hi everyone, i have had my flame angel for 3 weeks now, and hes eating well and constantly grazing on th LR, however over the last few days his "forehead" for want of a better anatomical description, seems to have dark patches developing on it, like a burgundy hue to them.

Any idea what this could be?

No damage to the area, or any other part of him, colours very vibrant elsewere, eyes nice and clear etc

Any ideas would be brilliant!