A、Blue is a lucky color. B、Blue is a color of grass and leaves. C、Blue is a kind of jazz. D、Blue is a sad and thoughtful color.

Many expressions in English use colors. These expressions show how people feel about the colors. Different colors can describe different feelings of people. For example, people associate red with a strong feeling like anger. When someone is very angry, people say that he or she sees red. Red is an active color. A red-letter day is a lucky day. When criminals are caught in the middle of a crime, people say that they were caught red-handed. Green is the color of grass and leaves. When someone grows plants well, people say he has a green thumb. Blue is a sad, thoughtful color. When someone is very sad, she says she is blue. The blues is a kind of jazz that is usually very sad and slow.