Is he marbling?

[lks10300]

I know the first picture isn't high quality, but when I got him in September Zippy was completely blue. I first noticed that the tip of one ventral fin turned white, and now both sides have white tips. A few days ago I noticed the reddish change between the anal fin and the body which has spread. At first I was worried something was wrong, but now I'm pretty sure he's marbling. How long will it take for the colors to change a ton?? I'm excited to see what color he ends up!!

[callistra]

No, he has fin rot... you might want to post on the disease forum with this: http://www.bettafish.com/showthread.php?t=49233

[lks10300]

I know he has fin rot, I went to visit my family for a few weeks and left him with a friend, and was pretty upset about how bad it was when I got back. I have been treating the fin rot, but have not noticed the color changes before, that's why I was curious about marbling..does the color change mean that the fin rot is getting even worse??

[Pasdio]

He looks to be a solid colored betta in your first pic and marbles generally start out white and then slowly develop color over a few months-at least from what I've seen. So the reddening in color could be due to some ammonia burns. Keep his water clean and warmed with a heater and it should get better. c:
Though I'm no expert, so posting in the diseases and emergencies subforum might be a good idea. If you do end up posting in there be sure to fill this (http://www.bettafish.com/showthread.php?t=49233) out when you make a new thread.