The very first thing I'd do... is Seperate them. They might be getting along now, but by moving the female into the males tank, even if she was healthy before, it sounds like she's picked up whatever he has. To save on treatment costs you could leave them in the same tank and just divide them, using a diy divider or a store bought one, but once they feel better they will probably start to fight, and its not a risk you should take. If you can't divide the tank, move the girl back to her tank, and maybe if you think ther're lonely try to find a way where they can see each other, but not be in the same tank.
2ndly, I would test your water and find out what all the stats are for it.
If everything is normal, I would then lower the water level to about half, since it sounds like they're having trouble reaching the surface.
Next, examine your fish. If the lighting isn't that good (Not sure what size tank you have) take them to a room where the light is bright, or use a bright flashlight, and examine them.
Do they have any odd colorations on them, any white, any spots, any fuzz? any red marks or sores?
You say they've had color loss, can you see anything odd around their gills?
umm, after you do that, report back with the details and either post them here or in the emergency section.