Complementary Color Generator

Complementary colours are pairs of colours that sit directly opposite each other on the HSL colour wheel - exactly 180° apart in hue. When placed side by side, complementary colours create the strongest possible visual contrast and make each other appear more vibrant. Common examples include red and cyan, blue and yellow, and green and magenta. Our complementary colour generator instantly finds the exact complement for any colour you enter.

1. Enter a colour: Type any HEX value (e.g. #FF6B6B) or use the native colour picker to visually select a colour. You can also click any sample colour to instantly populate the input. All processing runs locally in your browser - your data never leaves your device.
2. Complementary and split-complementary are computed: The complementary colour generator automatically calculates the exact opposite hue (180° away) as well as the split-complementary variants (150° and 210° away). Saturation and lightness are preserved, so you get harmonious colours that match the intensity of your base colour.
3. Review and export: View all colours as visual swatches with HEX, RGB, and HSL values. The colour wheel shows the exact position of each colour. Use one-click copy to grab individual values or copy all colours at once for your design workflow.

• Complementary: A two-colour scheme using the base colour and its exact opposite (180° apart). This creates the highest possible contrast and is ideal for drawing attention to specific elements. Use complementary pairs for call-to-action buttons, error states, and high-impact visual elements.
• Split-Complementary: A three-colour scheme using the base colour plus the two colours adjacent to its complement (150° and 210° from the base). This provides nearly as much contrast as a complementary scheme but with more nuance and flexibility. Split-complementary is often preferred for UI design because it offers three distinct colours that work well together.
• When to use each: Use complementary when you need maximum contrast with just two colours. Use split-complementary when you need a three-colour palette that is still high-contrast but offers more design flexibility. Our complementary colour generator provides both options automatically.

Complementary colours work because of how the human visual system processes colour. When we see a colour, our eyes automatically anticipate its opposite. When the complementary colour is present, it satisfies this visual expectation and creates a sense of balance and completeness. This is why complementary schemes feel naturally harmonious despite their high contrast.

In digital design, complementary colours create clear visual hierarchy. Use the base colour for primary elements and the complementary colour for accents, calls to action, or elements that need to stand out. The split-complementary variants can serve as secondary accents, background variations, or interactive states. Our complementary colour generator makes it easy to explore these relationships and find the perfect colour pair for your project.