Betta fin loss assistance needed

[tuners]

I've had my Betta for a few months now, and with the whole virus situation, I had to make a 4-hour drive back home with him. I've been noticing his fins aren't looking as great as they used to - I've attached some old pics for comparison. I'm worried it might be fin rot - should I try using aquarium salts to help him out? Also, I've noticed his fins are kinda see-through now, and they're not the yellow they're supposed to be for a blue mustard male. I've heard some people say fin rot can cause color loss, but I've never seen his fins be yellow in the first place. Any ideas on how to enhance his colors would be awesome.

[starweave]

It definitely looks like fin rot to me. Can you tell me more about your tank setup - what's the size and how often do you do water changes? Also, what are your current water parameters? If you get those things dialed in, his colors should start to pop once he's in ideal conditions.