The type of betta fish food you choose is very important to the overall health and appearance of your betta fish. Some betta fish can be particularly picky eaters as well, so you may have to try a few different things until you find out what works best for your betta and also for you.
There are many different betta fish food options on the market, from flakes and pellets up to frozen and even live foods. The fresher the food - the better the nutrition. If you're up for it, there are many brine shrimp breeding kits available that will give you an endless supply of highly nutritious betta fish food that will keep your betta happy and healthy for years to come.
If live food is too much for you to handle, frozen brine shrimp and frozen bloodworms are excellent choices - most of the nutrients are preserved, and the flavor is much better than pellets or flakes, so your betta is much more likely to accept it.
Many betta fish really enjoy freeze dried bloodworms and shrimp as well, giving you another option to add. If you decide to use pellets or flakes (and your betta will accept them), choose one that is specifically designed for betta fish in order to ensure they get all of the proper nutrients.
There are many betta fish food options that include "color enhancers," designed to increase the coloration of your fish. While it may sound like "mad science," this does actually work, at least from the higher quality brands. They use ingredients such as krill, red algae, shrimp and plankton which contains the pigments fish use for their own colors. While this won't turn a white fish red, it will help your fish maintain its natural color and beauty.
Regardless of which type of betta fish food you use, make sure you choose a high quality brand. While it may be a few dollars more, it will do wonders for the health and appearance of your finned friend. It will also help your betta resist and recover from disease, which saves money on medicines and treatments.