About Colorfinch

How values are calculated

• RGB, HSL and OKLCH are converted from the hex code with the open-source culori library.
• Contrast ratios follow the WCAG 2 definition of relative luminance. Pass or fail is decided on the exact ratio, so 4.49:1 fails AA even though it rounds to 4.5.
• CMYK uses the standard simple screen formula. It isn't a print conversion; real print values depend on your paper, inks and color profile.
• Lighter and darker steps mix the color toward white or black in even steps.
• Matching colors rotate the hue on the HSL color wheel. Closest color names use CIEDE2000, a measure of how different two colors look.
• Suggested passing colors in the contrast checker change only lightness, in OKLCH, so the hue stays the same.

Where names and hex codes come from

Each color in our data is labeled with its source:

• CSS colors use the official values from the CSS color standard.
• Reference colors were checked against Wikipedia's “List of colors” pages, leaving out any values sourced from Pantone.
• Common colors use widely used values that we haven't yet confirmed in that reference. We confirm each one before its page goes live.

Some colors have more than one well-known value. Brown is an example: we use #964B00, the value most color references show, while CSS defines brown as #A52A2A. Color pages say so where it matters.

Colorfinch isn't affiliated with Pantone and doesn't publish Pantone names, numbers or equivalents.

Your privacy

The tools run in your browser. Images you use in the image tools are never uploaded. See the privacy page for details.

Spotted a problem?

If a value looks wrong or something doesn't work, please get in touch.