Faded betta

Question
I recently bought a male Betta. (About 2 weeks or so) He WAS deep blue/black, with red fins.  He lives in a decent sized bowl on my desk.  I normally feed him a small pinch of betta flacks two times a day. He is usually quite quick to get to his food at eat most, if not all of what I give him.  yesterday afternoon, I left for the night, feeding him right before I left. Its been a little less than a day in total since he's eaten, yet now that I just fed him, he doesn't seem too interested in the food.

The more pressing matter is he's no longer black. All the black has faded from him simply over night.  The only thought I could come up with as to why (and I don't know anything about fish really) is maybe his water needs to be changed, because I realize I haven't done that recently and he does live in a small bowl.

Why has the colour gone from my betta and what can I do to help him?

p.s. I have a bottle of betta fix remedy. It doesn't say on the bottle what it helps with, so would putting that in the water help him or hurt him?

Answer
Usually Betta's will start loosing their color if they are in dirty water, first change his water. Betta's can sometimes get  tired of eating flakes, in fact I don't know many Betta's that even like flakes. Try picking up some pellets at the store for him and see if he likes those better.

If he doesn't perk up or he's showing signs of being sick, ex: Spots, clouds or rotting fins, bloating, or still wont eat you might need some stronger medication.

Also, the Betta fix is a very mild treatment and it wont hurt him to add it in the water after you change it. Just follow the typical dose requirements and repeat if you need to.