problem with dwarf gourami
I've had my dwarf gourami for about 7 months now and it was perfectly fine when I left for a trip 2 weeks ago. The first image below is what it has looked like the entire time I have had it. Note the bright red and blue colors.
While I was gone, my friend fed my fish every other day and I had timers on my lights. She said she didn't notice anything wrong with my fish, but she wasn't really paying attention.
When I got back, I noticed that the gourami had lost nearly all it's red coloration and is nearly translucent now. Near the tail, there is a football shaped bump that appears to be an air bubble. I can't say if it's affecting his swimming or not. It seems to move around okay, and doesn't flop onto it's side or anything, but sometimes it looks as though the body sways one way because of the bubble. I thought that this might be the swim bladder that is now more apparent since his coloration is gone, but I'm not sure.
It's behavior has been for the most part normal. It swims around the tank normally and eats, though maybe not as aggressively as before.
All the other fish (black neon, neon, SAE, guppies) and ghost shrimp are normal. Any ideas what's going on? Thanks!