Color Blindness: Never Rely on Color Alone

Over 300 million people worldwide have color vision deficiency (CVD). The most common forms are:

• Deuteranomaly / Protanomaly (Red-Green Color Blindness): Affects roughly 8% of men and 0.5% of women. Red and green look like virtually indistinguishable muddy brown-yellows.
• Tritanomaly (Blue-Yellow Color Blindness): Less common; affects blue and yellow perception.
• Achromatopsia (Monochromacy): Complete absence of color perception; the user sees only shades of gray.

The Golden Accessibility Rule (WCAG 1.4.1):

'Color is not used as the only visual means of conveying information, indicating an action, prompting a response, or distinguishing a visual element.'

Always pair color with secondary cues: an icon, bold text, an underline, or descriptive label (e.g., <Alert type="error"> shows red background PLUS an alert icon PLUS the word 'Error:').