Betta Fish: Pretty fly for a betta guy

I got him at the grocery store 7 weeks ago. He was in good shape then, compared to so many cup fish. But today I noticed he's had a glow up 😍 Slowed the video down to get a good look. He's my first betta, but I've had a freshwater tank of some kind going continuously for 30 years. Just wanted to share 😁