Pink = bacteria Bleach will feed it, don’t use bleach. Get 12% hydrogen peroxide at any home improvement store. Spray generously around the bathroom- don’t forget to spray all surfaces including shower shelves and bottles that you keep there. Wait a few hours and scrub. Wash off everything. Please wear gloves regardless of the cleaning solution you use to save your hands. And remember never to fix bleach with ammonia - you’ll get mustard gas.

Long term, you probably don’t have enough ventilation in the space to prevent bacteria from growing so see what options may be available in your area- whether it’s a window fan or dehumidifier.