Popular Category:Articles with images not understandable by color blind users

The articles in this category contain images - typically maps, charts or diagrams - which color blind users find difficult to understand. Approximately one in ten white males have red-green color vision deficiency; this and other types of color vision deficiency affect around one in two hundred people of all races and sexes.[1] It is hoped that World Heritage Encyclopedia editors will revise these images so that they can be understood more easily, and remove them from this category.

Tips for editors

If you must use color to convey meaning or make distinctions between visual items (i.e. not merely for decoration), then this table shows "safe" groups of colors which are distinguishable to most color-blind people.

Black White Yellow Blue


Red Green

Brown Grey

  • Pick a maximum of one color from each box. Do not use more than one color from any one box.
  • Use large expanses of the color. If you're coloring text, use bold and a large font.
  • For small expanses of color, such as thin lines, clearly label them with text, or use non-color techniques such as font styles (bold or italic), line styles (dots and dashes) or cross-hatching (stripes, checkers or polka-dots).
  • Use bright mid-range colors, like children's crayons. Do not use light or dark variants of the colors.
  • If you need more colors... hard luck. Instead use non-color techniques such as labelling, font styles (bold or italic), line styles (dots and dashes) or cross-hatching (stripes, checkers or polka-dots).
  • If you are color-blind yourself, check your revised image with a color-sighted person to confirm the meaning is intact.

Useful utilities

These utilities are useful in determining whether a revised image is distinguishable to color-blind users. Typically they take a web page or image file as an input, and render a color-blind simulated image as output.

  • Etre.com colour blind simulator
  • Mozilla Firefox color-blind addons
  • Vischeck Daltonize color blindness simulator
    • Run Vischeck Daltonize online
    • Download Vischeck Daltonize for MS-Windows and Mac OSX
  • Sim Daltonism for Mac OSX. Freeware.
  • Color Oracle full-screen real-time simulator. For Linux, Mac OSX and Windows. Freeware.

See also


Pages in category "Articles with images not understandable by color blind users"

The following 2 pages are in this category, out of 2 total. This list may not reflect recent changes (learn more).

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