I love blue Angels.... The one in the first picture is beautiful. I will post, if you don't mind, a picture of mine tomorrow night.
Regarding food, I feed mine New Life Spectrum Thera +A Formula. They did not liked at the beginning, but after a week they started to eat it, now they love it. I also mixed with some garlic concentrate (liquid) from Kent.
Once in a while, I gave them Omega One flakes, and I know that sometimes they catch a shrimp from the tank as a snack...
In the past, I used to give to my Angels, once a week, Blood worms, as a treat, but I noticed that some were getting sick, with internal parasites. I even lost some Koi Angels, I don't know if the responsible source were the Blood worms or not, but since I change their diet, 6 months ago, no more illness.