huekit

Tiny, type-safe color toolkit — parse hex/rgb/hsl, convert, format, lighten/darken/mix, and WCAG contrast. Zero dependencies.

Theming, charts, and design tokens all need the same color chores: parse a hex, nudge the lightness, blend two shades, check the contrast. huekit does them in one small, typed package — parse hex/rgb/hsl, convert and format, and manipulate, with WCAG luminance and contrast built in. Zero dependencies.

import { lighten, mix, contrast, toHex } from "huekit";

toHex(lighten("#3498db", 0.15));  // "#74b9e7"
toHex(mix("#ff0000", "#0000ff")); // "#800080"
contrast("#000", "#fff");         // 21

Why huekit?

• Parses what you paste. #rgb / #rgba / #rrggbb / #rrggbbaa, plus rgb()/rgba() and hsl()/hsla() in comma and modern space/slash syntax.
• Round-trips. hex ↔ rgb ↔ hsl, with alpha preserved throughout.
• Manipulation that reads well. lighten, darken, saturate, grayscale, mix, withAlpha.
• Accessibility built in. WCAG luminance, contrast (1–21), and isReadable for AA/AAA checks.
• Ergonomic. Every function takes a CSS string or an { r, g, b, a } object.
• Typed & tiny. Full types, ESM + CJS, zero dependencies.

Install

npm install huekit
# or: pnpm add huekit  /  yarn add huekit  /  bun add huekit

Parse & format

import { parse, toHex, toRgbString, toHslString } from "huekit";

parse("#3498db");              // { r: 52, g: 152, b: 219, a: 1 }
parse("rgba(0, 128, 255, .5)"); // { r: 0, g: 128, b: 255, a: 0.5 }
parse("hsl(210 50% 53%)");     // { r: 75, g: 135, b: 195, a: 1 }

toHex("rgb(52, 152, 219)");          // "#3498db"
toHex({ r: 255, g: 0, b: 0, a: 0.5 }); // "#ff000080"
toRgbString("#3498db");              // "rgb(52, 152, 219)"
toHslString("#ff0000");              // "hsl(0, 100%, 50%)"

Convert

import { rgbToHsl, hslToRgb } from "huekit";

rgbToHsl({ r: 255, g: 0, b: 0, a: 1 }); // { h: 0, s: 100, l: 50, a: 1 }
hslToRgb({ h: 120, s: 100, l: 50, a: 1 }); // { r: 0, g: 255, b: 0, a: 1 }

Manipulate

import { lighten, darken, saturate, grayscale, mix, withAlpha } from "huekit";

lighten("#3498db", 0.1);   // +10% lightness
darken("#3498db", 0.1);    // -10% lightness
saturate("#3498db", -0.2); // desaturate
grayscale("#3498db");
mix("#000", "#fff", 0.25); // 25% toward white → dark grey
withAlpha("#3498db", 0.5);

Amounts are 0–1 (percentage points of HSL); mix weight is how much of the second color to use.

Accessibility

import { luminance, contrast, isReadable } from "huekit";

luminance("#fff");              // 1
contrast("#000", "#fff");      // 21
isReadable("#777", "#fff");    // false (below AA 4.5)
isReadable("#000", "#fff", 7); // true  (AAA)

Pairs well with

Need	Use
Clamp / lerp / remap numbers	@billdaddy/mathkit

Contributors ✨

This project follows the all-contributors specification. Contributions of any kind are welcome — code, docs, bug reports, ideas, reviews! See the emoji key for how each contribution is recognized, and open a PR or issue to get involved.

Thanks goes to these wonderful people:

Tung Tran 💻 🚧

License

MIT © Tung Tran