Betta Fish: Is this color change or is something wrong?

My daughter was given this betta and a few other fish as a gift last month (without asking me first 😭) so I'm still coming up to speed on all the ins and outs of caring for it despite doing lots of research. Please be kind, we're doing our best to take care of them and learn.

I haven't noticed any issue with him before now, but when I finally received and installed the light I'd ordered, I noticed some light patches/spots on him that I'm unsure about. My first thought was maybe something fungal, but the a lot of the white actually looks very shiny/sparkly when he moves around, which you can kind of see in the video. Is this a color pattern emerging, or something that needs treatment?

He is living very peaceably in a 15 gallon tank with six little neon tetras and three kuhlii loaches until I can afford a bigger setup. I'll be adding more plants as I can get more cuttings from my local plant group.

The water has been a little cloudy (ironically) since I added a water clarifying tablet thinking it would clean up any gunk on the gravel I didn't see (lesson learned, it was crystal clear before that🤦‍♀️). The color is from a piece of mopani wood. The nitrates and nitrites are zero, ammonia is ~0.5ppm right now (using sea chem prime daily), temp is 79 degrees.