Practical color knowledge

Web Color and CSS Guides

Learn CSS text, backgrounds, links, color formats, contrast, mixing and opacity through practical examples.

Accessibility

How to Check Text Color Contrast for WCAG

Measure foreground and background contrast, understand AA and AAA thresholds, and fix failing text without guessing.

Color formats

Understand how Hex, RGB and HSL represent the same screen color, how alpha works and when each CSS format is most useful.

Color calculation

Learn how screen colors blend, how alpha compositing changes the visible result and how to build useful transition scales.

CSS states

Choose link, hover, visited and placeholder colors that remain recognizable, readable and keyboard friendly.

CSS basics

Learn the reliable ways to set readable text colors with CSS, including Hex, RGB, HSL, custom properties and accessible fallbacks.

CSS backgrounds

Set solid, transparent and layered CSS backgrounds while preserving readable contrast and predictable color output.