Is this color normal? Is it ok to feed my crickets goldfish flakes?

[froggit]

I read that goldfish flakes are a good source of protien for crickets, is this true. Will it effect my pacman?

My pacman is a grey color on his face and down the middle of his back. Is this normal? I would like him to be that bright green color on his body. The portrait picture is him now, showing the grey color. And the second pic was what he looked like in December. I hope he isn't sick>