How we compute color

Method

Naming: CIEDE2000 against 31,912 names

When you pick a pixel or paste a code, we search the full community-maintained color-name-list dataset: 31,912 named colors. The search does not use RGB distance, which disagrees with human eyes badly enough to name obviously wrong matches. We convert both your color and every candidate to Lab space and rank by CIEDE2000, the color-difference formula the printing industry uses for quality control. The top match becomes the primary name; the next four appear as alternatives with their ΔE distances, because naming at the boundaries is genuinely subjective.

Most colors have no human-given name. For those, the engine builds a descriptive name from the color's own properties: a lightness band (Deep, Dark, Soft, Light, Pale), a chroma band (Dusty, Muted, Rich, Vivid), and a hue term from a 24-point wheel, so #3A7F2C reads as Green and #FFC0CB as Pale Muted Rose. The result is deterministic: the same hex always yields the same name. Every color therefore shows a name, and when that name is descriptive rather than human-given, the closest named match is shown right beside it with its ΔE, so the distinction is never hidden.

Method

ΔE: what the distances mean

ΔE (delta-E) measures perceived color difference. As a rule of thumb: below 1.0, differences are invisible to almost everyone. Below 2.3, most people can't tell two colors apart. From 2.3 to 5, colors read as matching at a glance. From 5 to 10, the difference is obvious side by side. Above 10, they are just different colors. Our compare pages use exactly these bands.

Palettes

Palettes: OKLCH, not HSL spin

Harmonies, tints, shades, and tones are computed in OKLCH, a perceptually uniform color space. Rotating a hue in OKLCH keeps apparent lightness steady, where naive HSL rotation makes some results glow and others turn muddy. When a computed color exceeds what screens can display, we compress its chroma while holding hue and lightness constant, never by clipping channels, which would shift the hue itself.

Method

Contrast: WCAG 2.x

Contrast ratios use the WCAG 2.x relative luminance formula, the current legal and de-facto standard. AA requires 4.5:1 for normal text and 3:1 for large text; AAA raises those to 7:1 and 4.5:1. Our contrast fixer walks a color's OKLCH lightness until the target ratio passes, keeping hue and chroma, so the fix still reads as your color.

Method

Mixing: two honest models

Paint results use red-yellow-blue pigment interpolation, the standard computational stand-in for subtractive mixing. Light results use additive blending. Real pigments vary by brand, binder, and ratio, so mix pages state their results as screen approximations of physical behavior, not lab measurements.

Method

The limits we can't compute away

Photos carry their lighting: a warm lamp shifts every pixel before we ever see it. Screens differ in calibration, brightness, and gamut, so the same hex looks different on two monitors. Printed color depends on inks, paper, and profiles we can't see from here. And metamerism means two materials can match under one light and split under another. Where these limits touch a feature, the page says so in plain text. Reference values for standards like RAL are widely published approximations, labeled as such, and we never print proprietary Pantone values.

Privacy

Privacy, while we're being precise

All image analysis runs in your browser. No photo, pixel, or derived color ever reaches a server, which you can verify in your browser's network inspector: the analyzer makes no upload requests. The full details live in our privacy policy.