Color diagnosticsIn-browser · no uploads

Palette Clinic

A second opinion for your palette. Paste your colors or drop in an image: you get findings, the numbers behind them, and a treatment plan you can apply in one click.

Your palette

Edit a hex code, click a swatch to pick a color, paste a list, or import from an image. Lock any color you do not want the fixer to touch.

Diagnosis

Every check runs on measured values: lightness, chroma, hue, contrast and color vision. Fixes keep what they can and tell you what they change.

Hue and lightness

The wheel shows where each color sits and which harmony pattern fits best. The ladder shows whether the palette has a real range from light to dark.

Contrast

Every text and background pairing, scored with WCAG 2, APCA or both. Select a pair to see it at real sizes and fix it.

Roles and preview

Give each color a job. The preview uses your roles, in light and in dark, on a landing page, a dashboard and a form.

Shade ramps

Eleven steps per role, each built to hit a set contrast against white, so every step has a known job. Click a step to add it to your palette.

System tokens

Hover, pressed, disabled, focus ring, links and status colors, derived from your roles and checked in light and dark.

Color vision

How the palette looks to people with common types of color blindness.

Report and method

A record of what passed, what changed and how far it moved, plus the math behind every check.

Take it with you

Copy or save the finished palette as code or design tokens, with dark-mode values and shade ramps included.

About. Palette Clinic is a design aid. Its results are not a legal statement of WCAG conformance, and the harmony, loudness, vibration and color-vision thresholds are adjustable heuristics, not standards. Your colors and images are processed in your browser and are not sent anywhere; saved versions stay in this browser. There is no analytics. APCA is a published model from Myndex Research for the draft WCAG 3; this page reimplements the 0.0.98G-4g formula and is not affiliated with or endorsed by them. Lightness, chroma and hue are measured in OKLCH. WCAG 2 contrast is relative luminance, shown rounded down so a 4.49 never reads as 4.5, and checked on the final 8-bit hex value. APCA is Lc from the 0.0.98G-4g model with text color first; values are shown without sign and rounded down. Color vision simulation uses the Machado, Oliveira and Fernandes (2009) matrices at full severity. Harmony fitting tests six hue patterns at every angle and penalizes patterns with more slots, so a bigger pattern only wins when it explains the colors better. Image colors come from k-means clustering in OKLab on a downscaled copy that never leaves your browser. Everything runs in the page; your palette and saved versions live in this browser.