Color guides and tools
Practical explanations and focused utilities for choosing, converting, and checking colors.
Open Contrast Lab
Test any foreground and background pair, preview interface elements, and generate accessible corrections.
How hex colors work
Understand six-digit and shorthand hex notation, RGB channels, and URL-friendly color codes.
Color contrast
Learn what WCAG contrast ratios measure and how to choose readable foreground colors.
Building palettes
Use tints, shades, complements, and analogous colors without losing visual hierarchy.