About PaletteUI

PaletteUI is a free, independent website with a small, focused set of color tools for designers and developers, plus a handful of guides and a browsable Color Museum. Rather than open with a mission statement, here’s a straight account of what this site is, what it deliberately is not, and how it stays free — so you know exactly what you’re getting before you use anything.

What this site is

PaletteUI covers the small, concrete color decisions you make while working in code and in mockups: checking whether text has enough contrast against its background, converting a color between HEX and RGB, lightening or darkening a color by a set amount, and working out the flat, opaque color you end up with behind a semi-transparent layer. Every tool runs entirely in your browser. There’s nothing to install, no account to create, and the colors you type aren’t sent anywhere or stored.

What this site is not

It’s not a full design suite, a component library, or a plugin for another app. It won’t save your work, sync files, or collect the values you enter. PaletteUI is also not affiliated with the W3C, the WCAG working group, Adobe, any browser vendor, or any brand it happens to mention — it simply implements the same well-documented, publicly available color maths those standards describe. The tools give general information and quick estimates, not professional accessibility, branding, or legal-compliance advice. For anything you’re shipping to real users, treat the numbers here as a first pass: verify against the official WCAG specification and test with real assistive technology and real displays before you rely on them.

The tools

Six calculators do the day-to-day work, and each one shows its result instantly with a live preview:

• Contrast Ratio Calculator — measures the WCAG contrast ratio between a text color and its background and tells you whether it passes AA and AAA for normal and large text.
• HEX to RGB Converter— turns any CSS hex color (3- or 6-digit, with or without the #, any case) into its red, green, and blue channel values.
• RGB to HEX Converter— takes red, green, and blue values and returns a clean lowercase 6-digit hex code, clamping anything out of range.
• Tint Calculator— mixes a color toward white by a percentage and gives the lighter tint as hex and RGB.
• Shade Calculator— mixes a color toward black by a percentage and gives the darker shade as hex and RGB.
• Alpha Blend Calculator— works out the solid color you get when a semi-transparent foreground sits over a background — the same maths behind CSS rgba() and opacity.

Guides and the Color Museum

Beyond the calculators, the blog and learn sections hold plain-language guides on contrast, color models, tints and shades, and getting predictable color out of the browser. The Color Museum is a set of visual galleries; every entry, image, and fact in it is drawn from Wikipedia and Wikimedia Commons and credited as such.

How it stays free

PaletteUI is an independent, advertising-supported resource. Advertising is what keeps the tools open to everyone — there’s no paywall, no sign-up, and no premium tier. If a result looks wrong, a guide is unclear, or there’s a tool you wish existed, the contact page is the place to tell us.