Colors: A Major Accessibility Issue
"So we have to make everything black and white?" No. That's the first misconception I have to correct in every color accessibility training. RGAA Theme 3 has two fundamental rules: sufficient contrast between text and background, and information must not be conveyed by color alone. When you know that about 4% of men are color blind (3.2 million people in France alone), you understand why this matters.
WCAG Contrast Ratios
Keep this cheat sheet handy -- you'll need it regularly. Normal text (under 18px): 4.5:1 minimum for AA, 7:1 for AAA. Large text (18px+ or 14px+ bold): 3:1 AA. UI elements and graphics: 3:1. Inactive or decorative text: no requirement.
Verification Tools
Here's my toolkit -- pick the one that fits your workflow. Colour Contrast Analyser: free desktop app with a color picker, my go-to. WebAIM Contrast Checker: quick online check for any two colors. Chrome DevTools: the CSS color picker already shows contrast ratios, no extension needed. Stark for Figma/Sketch: essential for designers. RGAA Test: auto-detects contrast issues on your live site.
Don't Convey Information by Color Alone
Here are the classic traps everyone falls into: links that only differ by color (underline them!), form errors marked only in red (add an icon and text message), charts with color-only series (add patterns -- stripes, dots), status indicators like green "online" / red "offline" (add text or icons).
Designing for Color Blindness
Color blindness isn't one condition -- it's a family. Red-green (protanopia/deuteranopia) affects 8% of men. Avoid pairing red with green, green with orange, or blue with violet. Want to see your site through color-blind eyes? Chrome DevTools has built-in vision deficiency emulation (Rendering > Emulate vision deficiencies). Sim Daltonism on Mac filters your entire screen in real time -- it's eye-opening.
Creating an Accessible Palette
Here's the practical method in 5 steps: pick your brand colors, verify text/background contrast for every combination, create light and dark variants, test with a color blindness simulator (takes 2 minutes), and document allowed combinations in a design system.
An accessible palette is not a boring palette. I've seen gorgeous brand identities that are perfectly accessible. Vibrant, saturated colors can absolutely meet contrast ratios. Accessibility is a creative constraint, not a limitation.