Byleth gets a tan whenever he/she stays in the sauna for too long. I have a screenshot from my game, but I'm not sure how to hyperlink here.
Edit: Took a look at the screenshot and, yeah, she's red. I misremembered. I know how saunas work and figured the game was using leaps of logic to give the character a tan.
...that's not how saunas work or what they do, speaking as a Finn here.
Hot steamy air isn't even remotely the same thing as direct sunlight with its potpourri of EM radiation (tanning is protective response to the UV wavelengths specifically), it just temporarily makes you ruddy due to expanded blood vessels etc.
Not that you can't give yourself bonafide burns in one if you heat it too hot and stay inside too long ofc but that's plain old scalding.
^more widely her perspective's plain buggered in general, which that is one symptom of. You know how the lines representing surfaces oriented in the same direction are supposed to meet at an imaginary "ideal point" in the "distance" of the picture?
Yeah well these just point willy-nilly wherever the fuck way and have no connection with the orientation of the "ground level" plane indicated by Eun's legs and that screwdriver...
A for effort and all but Jesus Mary Josif Stalin this artist seriously needs to do some basic perspective and projection practice. (also elementary anatomy because lol buttplug tail)