Yellow is the complement of the color purple. This is based on the color wheel, where the colors directly opposite each other are considered complementary colors. Other complementary colors are red with green and blue with orange.
In addition to being opposite each other on the color wheel, complementary colors contain one primary color and one secondary color made up of the other two primary colors. For example, yellow is a primary color. Its complement, purple, is created by combining the other primary colors red and blue. A color's complement can be used in design to intensify the color. Purple will stand out and become more noticeable when placed next to yellow.