Mystery Angelfish death

Question
My one blushing angelfish's forehead tuned the color of an off avocado a while back but he never seemed sick, no clamped fin or discoloration of the gills, he had a very good appetite, even last night. When I fed them this morning, I realized that he wasn't there. I found him at the back of the plants, hiding with almost no life in him and his forehead was almost black. He wasn't stuck in the plants. What caused this? I've been doing regular water changes and giving them a healthy, varied diet. The other fish are fine, including another angel, neon tetras, swordtails, sunset platys, corries and a pleco. Water temp is at 27C

Answer
Hi there,
I'm sorry to hear about your angelfish.

It sounds very strange to me indeed. I haven't experienced such a thing before with my angels. Due to the light coloration of the Blushing angel variety it could be some infection showing up underneath the skin or some other internal problem.

Drastic color changes are also major stress symptoms. Could be environmental problems or some other internal issue.

The best thing I can recommend is a big water change. If he's not already too far gone, he may have a chance of recovery if he gets immune boosting clean water.

I do hope all goes well. Best of luck!
Karen~