Complementary (com-pluh-MEN-tuh-ree) colors sit opposite each other on the color wheel. Because they are opposites, they tend to look especially lively when used together. When you put complementary colors together, each color looks more noticeable.
Red and green are an example of complementary colors. Look at the painting Carnation, Lily, Lily, Rose by John Singer Sargent. The reddish-pink color of the flowers really stands out against the green background. Imagine if Sargent had painted all yellow or blue flowers instead. They would just blend in with the green (ho-hum).
TRY IT! Choose colors that are opposite each other on the color wheel. For example, you might choose blue and orange. Make a picture that uses both colors. Don't they make an interesting contrast? That's because the colors are opposites.