Complementary Color Finder
Find the opposite colour on the wheel, instantly.
How to use
- 1 Type a hex colour or use the colour picker.
- 2 Read the complement swatch and its hex value on the right.
- 3 Compare the two hue angles shown beneath each swatch.
- 4 Copy the complementary hex with one click.
About Complementary Color Finder
The Complementary Color Finder reveals the exact opposite of any colour on the colour wheel — the hue sitting 180 degrees away.
Complementary pairs create the strongest possible contrast, which is why designers reach for them when a call-to-action button needs to pop against its background, when a chart needs clearly distinct series, or when an illustration wants a vibrant, balanced feel.
Enter a colour as a hex value (with or without the leading hash, full six-digit or three-digit shorthand) or use the colour picker, and the tool converts it into HSL, rotates the hue by 180 degrees while keeping the original saturation and lightness, then converts back to RGB and hex.
Working in HSL rather than naively inverting the RGB channels means the complement stays at the same brightness and vividness, giving a result that actually looks like a matched pair rather than a muddy near-inverse.
Live swatches show both colours side by side along with their hue angles so you can judge the contrast at a glance, and the complement hex is one click to copy.
Greys, which have no hue, are handled gracefully and stay grey.
Everything runs locally in your browser with no uploads, so it is fast, private and works offline.
FAQ
How is the complementary colour calculated?
The colour is converted to HSL and its hue is rotated by 180 degrees, keeping saturation and lightness, then converted back to hex. That yields the true opposite on the wheel.
Why is the complement of a grey still grey?
Greys have zero saturation and therefore no hue to rotate, so rotating the hue leaves them unchanged — which is correct.
What hex formats are accepted?
Six-digit (#3498DB) and three-digit shorthand (#38D), with or without the leading hash. Shorthand is expanded automatically.