You click a forum you want to post on, then at the top of it on the left there's a new thread thing. For your fish, talk to OldFishLady. She is an expert and could help you more then me. Most likely it's just coloring, could you post a picture?
You seem like you are experienced... I need help... I got my betta fish a few days ago, and I got him at Walmart, so obviously they don't take too much care of the bettas. Tumble is blue, but he is gray at the front, it kind of looks a bit sickly. I thought once I had gotten him, took him home, & loved him and feeded him, it would get better. But it has just stayed the same. Is he sick? Thanks! And also, I'm new to this website... How do you post? Lol
It's some sort of infectiony fungus on her back. She's gotten that cottony fungus a lot in her past and has a high disease history, she is like seven now so she's on her leg. I'm not medicating this time because it seems like it would only hurt her.