Mold/Mildew??

[sourdough]

We've been in the FL panhandle for about the past 7 weeks. After about 4 weeks my wife complained to me about the yellowish/pinkish/orange residue I was leaving in the shower. I wasn't that I was aware of. She has been cleaning the walls and using a brush on the floor. Today she wiped down the walls inside the bathroom......yellowish/pinkish/orange residue came off on the towel. Before she wiped the walls she said she had put her hand on it and it felt tacky. Once wiped you could actually see the discoloration on the wall as it was wiped off.

We both shower daily and I try to leave at least one door open afterward. It has it's own AC vent. I do close the sliding door to the bedroom each night after taking a shower because the skylight over the shower is so bright in the AM. Reckon this is some kind of mold or mildew? With that color? It must have something to do with the moisture because it's not anywhere else. I have a vent fan in the bathroom but have not been running it. I just turned it on to see what happens. The heat has been pretty high here along with the humidity so I've ran the front bedroom AC in the afternoons. It works great but it sure seems to put out more moisture than the main one. It is a Dometic Penguin II 13,500. The sheets feel sort of damp after it's been on a while sort of like a swamp cooler, just not nearly as bad. Maybe that's a factor? Just trying to figure out if orange mold/mildew exists in anyones experience.