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Complementary Colour Finder

Find the colour directly opposite yours on the wheel.

  • Free
  • No signup
  • Nothing uploaded
  • No watermark
Open in Coolors

CSS custom properties

:root {
  --color-1: #2563EB;
  --color-2: #EBAD25;
}

Worked out in your browser. Nothing you enter or open is uploaded.

How to Use the Complementary Colour Finder Online

Complementary Colour Finder: before and after TEXT A YOUR INPUT COMPLEMENTARYCOLOUR FINDER DONE A RESULT

Finds the colour directly opposite yours on the wheel. Maximum contrast, which makes it excellent for a call-to-action against a brand colour and difficult to use over large areas — two saturated complements at full strength visibly vibrate against each other.

No software to install Free Works on any device

Step-by-Step Guide to Using the Complementary Colour Finder

  1. 1. Fill in the fields with your own numbers

  2. 2. The answer updates as you type — there is no button to press

  3. 3. Read the breakdown underneath to see how the figure was reached

Try it now

What is the Complementary Colour Finder?

Finds the colour directly opposite yours on the wheel. Maximum contrast, which makes it excellent for a call-to-action against a brand colour and difficult to use over large areas — two saturated complements at full strength visibly vibrate against each other.

Why Use Colour and CSS Tools?

Choosing colours that work together and writing CSS for shadows, gradients or grids takes a lot of trial and error. These tools show a live preview as you adjust, then hand you the colour codes or CSS to copy.

“See it first, then copy the code.”
  • Live previews while you adjust
  • Codes in HEX, RGB and HSL
  • CSS ready to paste
  • Designs checked for colour blindness
  • Palettes that work together
  • Readable text checked for contrast
  • Print colours in CMYK
  • Colours taken from photos

Popular Uses for Colour Pickers and CSS Generators

Designers and site owners use these for the same handful of jobs.

  • Brand colours Build a palette around a logo colour with matching tints, shades and accents.
  • Readable buttons Check that text on a coloured button passes the WCAG contrast ratio.
  • Card shadows Adjust a box shadow until a card looks right, then copy the CSS.
  • Page layouts Set up a CSS grid or flexbox layout visually instead of guessing values.
  • Print artwork Convert screen colours to CMYK and check bleed before sending a flyer to print.
  • Colours from a photo Pull the main colours out of a product photo to match a web page.
  • Colour blind checks See how a chart or poster looks to people with different kinds of colour blindness.
  • Button styles Design a gradient, glass or soft 3D style button and take the code.

What You Can Do with the Complementary Colour Finder

Exact where the spaces allow it, and says so where they do not

Contrast is reported against the WCAG thresholds, with the pass or fail stated plainly

Colour-blind simulation uses published transforms rather than an approximate filter

Why Use ToolXkit for Complementary Colour Finder?

Your files stay with you

Everything runs inside your browser. Nothing you open or type is uploaded to a server.

Design Tools for Different Users

Designers

Build palettes, test contrast and convert colours between HEX, RGB, HSL and CMYK.

Front-end developers

Generate CSS for gradients, shadows, animations and layouts and check it in a preview.

Design students

Learn how colour harmony and CSS properties work by changing them live.

Small business owners

Pick consistent brand colours for a shop sign, website and social posts.

Print designers

Convert colours for print and work out bleed, trim and pixel sizes.

Accessibility testers

Check contrast ratios and preview designs through different types of colour blindness.

Best Times to Pick Colours and Write CSS

These tools help when you are:

  • Starting a new brand or logo
  • Fixing text that is hard to read
  • Styling a button or card
  • Preparing a flyer for print
  • Matching a colour from a photo
  • Laying out a page with grid
  • Checking a chart for colour blindness
  • Converting a HEX code to RGB

Frequently Asked Questions

Answers to common questions about this tool.

Do I need to install anything to use the Complementary Colour Finder?

No. Complementary Colour Finder runs entirely in your browser — there is nothing to download, no extension and no desktop program. It works the same on Windows, macOS, Linux, Android and iPhone.

Is it safe to use the Complementary Colour Finder online?

Safer than the usual alternative, yes. Most online tools upload your file to a server you know nothing about, where it sits until someone deletes it. Here the file never leaves your device — the processing happens in the page itself, so there is no server copy to leak, retain or sell.

Can I copy the CSS straight into my project?

Yes. The generators give plain CSS that works in current browsers. Copy it into your stylesheet, then adjust class names or values to fit the rest of your design.

Is Complementary Colour Finder free for commercial work?

Yes. The colours, palettes and CSS you make are yours to use in client projects, products or anything else, with no credit required and no fee.

Why do my screen colours look different when printed?

Screens mix light in RGB, while printers mix ink in CMYK, and some bright screen colours cannot be printed. Convert to CMYK and ask your printer for a proof before a large print run.

What contrast ratio should my text have?

WCAG asks for at least 4.5 to 1 for normal text and 3 to 1 for large text. The Colour Contrast Checker shows whether your pair passes, so you can adjust before publishing.

Do I need to sign in to use Complementary Colour Finder?

No. There is no account to create. Open the page, adjust the settings and copy the result. Your choices are worked out on your own device and never leave it.

Further reading

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