1. plural of complementary; things that complete or enhance each other by providing what the other lacks
Usage: usually used in formal or technical contexts
2. in color theory, pairs of colors that sit opposite each other on the color wheel and enhance each other's vibrancy
Usage: art and design terminology

Examples

• Red and cyan are complementaries in the RGB color model.
• The two theories are complementaries that together explain the phenomenon.
• In design, using complementaries creates visual balance and contrast.
• The skills of the two partners are complementaries—one excels at planning while the other handles execution.
• Blue and orange are complementaries that appear vibrant when placed side by side.