Why can't hotel employees wear white socks?

Hotel waiters generally wear black pants and shoes (usually black shoes). Etiquette stipulates that black shoes must be matched with black socks (at least dark socks, never light and white socks). The reason for this regulation is to maintain the unity of pants, socks and shoes. It is very natural and appropriate to wear black pants, socks and shoes.

If you wear black trousers and shoes with a pair of white socks in the middle, it will look very abrupt and rude. It's like an upper suit shirt and lower leather shoes, but there is a pair of sweatpants in the middle, which is very inappropriate.

White socks are only suitable for white pants and shoes.