Designing for Color Blindness

Approximately 8% of men and 0.5% of women have some form of color vision deficiency (CVD). If you rely on color alone to convey meaning (like red for errors and green for success), you are failing accessibility standards.

The Rule of Secondary Indicators

Never rely solely on color. Always use a secondary indicator:

  • Forms: Use an icon (like a cross or checkmark) alongside the red/green border.
  • Charts: Use patterns (stripes, dots) or direct labels instead of relying on a legend mapping colors to lines.
  • Links: Keep underlines active. Do not remove them just because the text is blue.

Common Types of CVD

Protanopia/Deuteranopia: Red-green color blindness. The most common type.

Tritanopia: Blue-yellow color blindness. Much rarer.

Achromatopsia: Complete color blindness (monochromacy).

Interactive Tool: CSS Filter Simulator

We can simulate how your application looks using CSS SVG filters. Modern browsers support applying complex matrices to simulate CVD.

Status

Filter off.

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