Complementary Colour Generator

What Is a Complementary Colour Generator?

A complementary colour generator identifies the colour that sits opposite a selected colour on the colour wheel. Complementary colour pairs have contrasting hues and are commonly used to create visual distinction in graphic design, web design, branding and digital interfaces.

This tool accepts a six-digit HEX colour and calculates its complementary colour by converting the colour to HSL, shifting its hue by 180 degrees and converting the result back into HEX and RGB values. Both colours are displayed together so they can be compared visually.

Why Use the Complementary Colour Generator?

Finding a complementary colour manually can require colour-wheel calculations or a separate design application. This generator provides the result immediately and also displays useful colour values for digital projects.

How to Use the Complementary Colour Generator

Use the colour picker or enter a HEX colour to calculate its complementary colour.

1. Enter a colour — Type a six-digit HEX colour such as #0067F0, or select a colour using the colour picker.
2. Generate the complement — Select Generate Complement to calculate the opposite hue.
3. Review the results — Compare the original and complementary colours and view their HEX, RGB and HSL values.
4. Copy a value — Use the Copy buttons beside any colour value to copy it to your clipboard.

Find Complementary Colours Online

Complementary colours are created from opposing hues. In a traditional colour wheel, complementary pairs are positioned directly opposite one another. In digital colour models, the same relationship can be represented by shifting the hue value by 180 degrees while retaining the saturation and lightness.

For example, a colour with a hue of 30 degrees has a complementary hue of 210 degrees. Likewise, a hue of 120 degrees has a complementary hue of 300 degrees. Because the hue scale wraps around at 360 degrees, the resulting value always remains within the standard 0 to 359 degree range.

Complementary Colours in Web Design

Complementary colour combinations can help distinguish elements on a page. Designers may use a complementary colour for accents, buttons, icons, highlights or other interface elements while using the original colour as a primary design colour.

HEX, RGB and HSL Colour Values

HEX is commonly used in CSS because it represents a colour using six hexadecimal characters. RGB represents the same colour through red, green and blue channel values. HSL represents colour using hue, saturation and lightness, making it particularly useful when adjusting the relationship between colours.

How Complementary Colours Are Calculated

The generator first converts the entered HEX colour into its RGB components and then converts those values into HSL. The hue is shifted by 180 degrees while the saturation and lightness remain unchanged. The resulting HSL colour is converted back into RGB and HEX for display.

This produces a mathematically defined complementary hue based on the HSL colour model. The visual appearance of a colour pair can still depend on display settings, surrounding colours, brightness and the colour model being used, so the generated relationship should be considered a colour-selection aid rather than a guarantee of a particular visual contrast level.

Frequently Asked Questions