The primary colors in art are red, blue, and yellow. These colors are considered the foundation for all other colors, as they cannot be created by mixing other colors together. Artists can mix these primary colors in various combinations to produce a wide range of secondary colors: red and blue make purple, red and yellow create orange, and blue and yellow combine to form green. The understanding of primary colors is fundamental to color theory in art and design, enabling artists to create depth, contrast, and harmony in their work.