I use mild soapy water, cotton swabs and microfiber cloths if the dirt doesn't come of with just a damp cloth to begin with. I polish up parts with a resin based car polish, it's known to remove cloudy patches some times, but there's no guarantee. The yellow paint is probably delicate and you have to be careful not to rub too much. I would test with just a dab of polish on a cotton swab to check if the paint can take the treatment.