So you're forced to spend hours at the island each day to keep a tan? And if you only want a slight tan, you're screwed even more. You'd have to keep managing how much time to spend on the island and what accessories to wear. That's no fun. They should put a tanning booth in Shampoodle in the next game. Not sure if they'd want to promote that kind of unhealthy lifestyle, but you already got lazy villagers talking about bathing in syrup and jocks talking about stocking up on energy drinks so...
Yeah, there definitely needs to be something to control your tan. Maybe you should start as mildly tan, then use sunscreen to get lighter and something else to get more tan. They could just call it "skin cream" or something. I don't like that you have to wear certain clothes to prevent tanning or spend hours outside to get a tan, seems like there's room for improvement there for sure.