I dont know what the need to add more color to it would be

The color might be added to the fish food to please people, not the fish. They're always doing stuff like that. Haven't you seen all the cute little dog and cat treats in the pet stores? Your dog doesn't care if a biscuit is shaped like the Easter bunny, but then, your dog isn't the one making the purchase. And aren't the dog food commercials entertaining, with dogs doing happy dances when they are served their meals?

I guess we shouldn't be surprised at anything the pet food manufacturers come up with. Considering the garbage the American food industry creates for humans, why should we expect anything better when they manufacture food for our pets?

And BTW,
Even the wild racoons in my neighborhood are eating chinese take-out from my neighbor's overturned garbage cans. And FYI, they are grossly fat. The raccoons, that is. (And so are my neighbors, come to think of it.)