Complementary Color Calculator

About this calculator

A complementary color is the color diametrically opposite a given hue on the color wheel — pairing them creates the strongest possible contrast, which is why complementary schemes (blue/orange, red/green, yellow/purple) are a foundational tool in design, painting, and branding. This calculator finds it by converting your hex color to HSL (hue, saturation, lightness) and rotating the hue value by 180° while keeping saturation and lightness unchanged, then converting back to hex — the standard color-theory method for finding a true complement.

It also shows the alternative you get from a simple RGB inversion (subtracting each of the red, green, and blue channel values from 255), which produces a visually different result from the HSL-based complement — an RGB invert is the mathematical “negative” of a color, while the HSL hue rotation is the perceptually correct complementary color used in color theory and design tools like Adobe Color.