Palette — Colour System & Contrast Lab

Palette — Colour System & Contrast Lab — a premium, 100% offline digital tool by Aceplore. Runs entirely in your browser: no accounts, no subscriptions, your data never leaves your device.

A private, offline colour workspace that builds palettes and proves they're readable — real WCAG contrast, colour-blind simulation, shade ramps and one-click CSS, Tailwind and design-token exports.

30 built-in tools in one app. A dashboard with live contrast warnings; a generator that builds a full palette from one base colour; 50–950 tint and shade ramps; a WCAG contrast checker with AA and AAA verdicts; a full foreground-by-background contrast matrix; protanopia, deuteranopia and tritanopia simulation plus a non-colour-cue checklist; harmony sets, gradients, a HEX/RGB/HSL/HSB converter and mixer; light and dark themes with auto dark-mode derivation that flags breaks; hover, active and disabled state derivations; a live UI preview; exports to CSS custom properties, SCSS, Tailwind and W3C design tokens; a saved colour library, locked brand colours, paste-to-import, auto naming, palette comparison and a scored accessibility audit with ranked fixes.

The maths is real. Contrast uses WCAG relative luminance on linearised sRGB — black on white returns exactly 21:1. Colour conversions round-trip losslessly across 20,000 test colours.

What's included:

• Palette.html
• Quick-Start-Guide.html
• How-To-Use-Guide.html
• README.txt
• LICENSE.txt

Includes a personalized welcome wizard, an interactive guided tour, a ⌘K command palette, light/dark themes with 8 accents, and one-click JSON backup & restore. Works on any modern browser.

A design tool. Contrast and accessibility figures follow published WCAG formulas as guidance — they are a starting point, not a certification. Always test with real users and assistive technology.