Free color tools
Build and check accessible colors in your browser. Free, no sign-up.
Color System Builder
One brand color in. A complete light and dark UI color system out.
Contrast Checker
Check text and background colors against WCAG 2.2, and get the closest accessible alternatives.
Color Scale Generator
Turn one color into an 11-step scale from 50 to 950, and export it for CSS, Tailwind, or design tokens.
Brand Color to Dark Mode
One brand color in, a checked dark-mode color system out, with the reasons for every choice.
Color Converter
Convert a color between HEX, RGB, HSL, and OKLCH, with values that read back as exactly the same color.
shadcn/ui theme generator
A complete, contrast-checked shadcn/ui theme for light and dark mode from one brand color.
Tailwind color system generator
A semantic Tailwind CSS v4 color system with light and dark mode from one brand color.
Dark mode palette generator
A readable, consistent dark-mode palette from one brand color, with the light mode alongside.
Website Color Audit
see every color a page uses and where contrast fails
Palette Generator
press space for palettes with readable text in light and dark
Color pages
formats, scales, and accessible pairings for 1,000 colors