This study explored the theory and applications of complementary colors using a technology-based activity designed from the perspective of STEAM education. Complementary colors and their areas of use were examined from the perspective of physics, mathematics and art, respectively. The study, which benefits from technology, makes the theory of complementary colors accessible to all through practical applications and provides a multidisciplinary, integrated and innovative technique of teaching the subject of colors, which could be used to teach complementary colors.