Show professionalism and protect privacy. A doctor's WeChat avatar is set to black and white because it can show their professional image. Black and white photos usually give people a sense of solemnity and concentration, which is consistent with the professional characteristics of doctors. And setting a black-and-white WeChat avatar can protect your privacy. Black-and-white photos can provide more abstract and fuzzy images, which is helpful to reduce the disclosure of personal information compared with color photos.