What is your favorite color? Do you like yellow, orange, and red? If you do, you must be an optimist , a leader, an active person who enjoys life, people and excitement. Do you prefer grays and blues? Then you are probably quiet, shy and you would rather follow than lead. If you love green, you are strong-minded and determined. You wish to succeed and want other people to see you are successful. At least this is what psychologists tell us, and they should know, because they have been seriously studying the meaning of color preference , and the effect that colors have on human beings. They tell us that we don't choose our favorite color as we grow up. If you happen to love brown, you did so as soon as you opened your eyes, or at least as soon as you could see clearly. A yellow room makes us feel more cheerful and more comfortable than a dark green one, and a red dress rings warmth and cheer to the saddest winter day. On the other hand, black is depressing . Light and bright colors make people not only happier but more active. It is a fact that factory workers work better, harder, and have fewer accidents when their machines are painted orange rather than black or dark gray. Remember, then, that if you feel low, you can always brighten your day or your life with a new shirt or a few colorful things. Remember also that you will know your friends and your enemies better when you find out what colors they like and dislike. And don't forget that anyone can guess a lot about your character when you choose a piece of handkerchief. The main idea of this passage is  _  .
one's color preference shows one's character you can brighten your life with wonderful colors psychologists have been studying the meaning of color preference one's color preference has something to do with his character and colors have effects on human beings