Wiki > The GUI > Other > Designing for Colour Blindness

Some people are colour blind (to varying degrees). About 7% of men and <1% of women are colour blind. The most common form of colour-blindness is red-green colour blindness (inability to distinguish red from green). A smaller number of people have blue-yellow colour blindness.

This page provides some tips on designing displays that are suitable for people with normal vision and those with colour blindness.

1. Don't rely on colour alone to distinguish between elements of the display. Combine colours with different shapes (with outlines, in black, say) or text.
2. In graphs, combine colours with line styles (solid lines, dashed lines, alternative dots-dashes, etc.).
3. Avoid colour combinations that colour-blind people find difficult to distinguish.
   1. Colour Combinations illustrates some poor and some good colour combinations.
   2. As a simple rule (for red-green colour blindness): replace red with magenta or green with turquoise.
4. Download the ColorOracle tool. It temporarily changes the colour balance of your screen to show how it appears to a colour blind person. Use it when designing displays & graphs. NOTE: when running the ColorOracle exe file, a small icon will appear on your taskbar (next to the date and time); if it's not there, check your hidden icons.
5. The ColorOracle site has more comprehensive design advice.