Though many of the common fish foods have questionable ingredients, there are several sources for high-quality fish feeds that do not contain artificial coloring. One the best flake foods for tropical fish is Zoo Med Spirulina 20. It contains high-quality proteins and no artificial coloring.
Click here to buy Zoo Med Spirulina 20 Flake Fish Food. You can also find it at most pet stores.
Here is a good reference for several other fish foods with ratings and detailed analysis: Fish Food Ingredients Analysis
← Is there any natural fish food I can use?