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Complementary Color Finder

Enter any hex color to find its opposite on the color wheel, with HEX, RGB, and HSL values ready to copy.

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What is the Complementary Color Finder?

Enter any color and instantly find its complement — the color directly opposite on the color wheel. Complementary pairs give the strongest contrast, so they're handy for buttons, highlights, and accents that need to stand out.

Type a hex code or pick a color visually. The tool shows both colors side by side with their HEX, RGB, and HSL values, ready to copy into your design.

How it works

Enter a color with the color picker or by typing a hex code, and the tool finds the hue opposite it on the color wheel:

  1. Convert — The hex value is converted to RGB, then to HSL, where hue, saturation, and lightness are separate and easy to adjust.
  2. Rotate the hue by 180° — For example, a hue of 30° becomes (30 + 180) % 360 = 210°. Saturation and lightness stay the same so the intensity matches.
  3. Convert back — The result is converted to RGB and hex for use in design tools and CSS.
  4. Compare — Both colors appear as swatches with their hex, RGB, and HSL values. Copy any value with one click, and toggle the RGB/HSL details on or off.

Examples

Find complementary color for Red

Get the strongest-contrast pairing for a red accent.

#FF0000
 
#00FFFF

Pair a blue button with an accent

Find a highlight color that stands out against blue.

#0000FF
 
#FFFF00

Check a green background combination

See the contrasting color for text or badges on green.

#00FF00
 
#FF00FF

Frequently asked questions

What is a complementary color?

A complementary color is a color that is directly opposite another color on the color wheel. When placed next to each other, complementary colors create the strongest contrast and can make each other appear brighter and more vibrant. They are often used in design to create visual interest and balance.

How is the complementary color calculated?

The complementary color is calculated by rotating the hue component of a color by 180 degrees on the HSL (Hue, Saturation, Lightness) color wheel. The saturation and lightness values typically remain the same as the original color.

Can I input colors in formats other than hex?

Currently, the tool primarily accepts hexadecimal color codes as input, and also allows selection via a color picker which outputs hex. The results are displayed in Hex, RGB, and HSL formats for convenience.

Why are RGB and HSL values important?

RGB (Red, Green, Blue) is an additive color model used for displaying colors on screens, while HSL (Hue, Saturation, Lightness) is a more intuitive model for designers to understand and manipulate color properties. Providing both allows for flexibility in different design workflows and applications.

Is this tool suitable for print design?

While this tool provides complementary colors based on the RGB/HSL color model, which is screen-oriented, the principles of complementary colors apply universally. For print design, you may need to convert the resulting RGB/Hex values to CMYK (Cyan, Magenta, Yellow, Key/Black) using a separate tool or software, as CMYK is a subtractive color model used in printing.

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