Women: There's no formal dress code for general ticket-holders, but a smart-casual dress is usually the way to go. The general rules are "not too short and not too tight." Lots of ladies favor white or cream.
Men: No formal dress code for general ticket-holders, but torn jeans, running vests, dirty trainers, and sports shorts are not allowed. In the members area, the dress code is more defined, with men required to wear a lounge suit or tailored jacket, shirt, tie, trousers, and dress shoes.