Angels are usually depicted wearing white robes. The ancient Greeks wore white to bed to ensure pleasant dreams. The Egyptian pharaohs wore white crowns. The ancient Persians believed all gods wore white . It's considered good luck to be married in a white garment.
White heat is a state of intense enthusiasm, anger, devotion, or passion.
To white wash is to gloss over defects or make something seem presentable that isn't. White water is the foamy, frothy water in rapids and waterfalls. The ancient Egyptians and Romans used black for mourning, as do most Europeans and Americans today. Black humor is morbid or unhealthy and gloomy humor. In China, black is for little boys.