What are the most common types of colour blindness?+
Deuteranopia (green-blind) and protanopia (red-blind) together affect about 8% of men. Both cause difficulty distinguishing red from green. Tritanopia (blue-yellow) affects less than 1%. Achromatopsia (complete colour blindness) is very rare.
How does WCAG 1.4.1 relate to colour blindness?+
WCAG Success Criterion 1.4.1 requires that colour is not the only visual means of conveying information. Form validation errors must not rely on red colour alone - they also need icons, text labels, or patterns.
What is the safest colour palette for colour blind users?+
Blue and orange are distinguishable by all types of colour blindness. Avoid red-green combinations for critical information. Use patterns or textures in charts in addition to colour. IBM, Google, and Okabe-Ito palettes are designed for accessibility.
Can I check my website for colour blindness issues?+
Screenshot your UI, upload it here, and check all simulation modes. Focus on charts, status indicators, form validation, and links. Also use browser extensions like Colorblinding or Chrome's built-in accessibility inspector.