Not Sure If My Betta Has Fin Rot

[Bossman]

I have heard that fin rot is like black on a bettas fin. I am not sure if that is what my bettas case is or if it is a marble betta. If it is a marble what color would he turn into or is it just like certain spots on his body with black?

Ps-
Disregard the backgrounds I was cleaning their tank when i realized lol

[callistra]

That's normal coloring :)

[Bossman]

I am guessing you mean he is marble? When I first got him he was completely white. It has been about 2 weeks now and his tail has got these black stripes

[chardzard]

finrot start out reddish then look black like after u burn something