Not all the time. It's kind of a pain in the ass to use. For raw food like shrimp and scallops I soak it in a diluted solution of the powder over night. For dry food I mist the food and sprinkle a bit of the powder over the food...then freeze the food prior to use. They make a flake and also a wafer. My experience with both of those is to use it sparingly for larger fish. It breaks up easy and and can be pretty messy.
I don't have before and after pictures. I generally use it more heavily prior to a contest. As pointed out, the best recipe for overall color development is fresh clean water and a varied diet. People who feed their fish diets that are not consistent with what they eat in the wild will not experience (ultimately) the true colors of the species. Research what the fish eats in the wild and act accordingly.