color-blind

Description

Simulate color blindness by converting RGB hex codes. This is a node.js port of the daltonize code by mudcu.be. See Links for more information.

Getting Started

Install the module with: npm install color-blind

var blinder = require('color-blind');
blinder.protanopia('#42dead'); // result: "#d1c4a0"

Color Blindness Table

Group
Trichromat 3 good cones	Normal
Anomalous Trichromat 2 good cones, 1 bad	Protanomaly low red	Deuteranomaly low green	Tritanomaly low blue
Dichromat 2 good cones, 1 blind	Protanopia no red	Deuteranopia no green	Tritanopia no blue
Monochromat 1 good cone, 2 blind/bad	Achromatomaly almost no color	Achromatopsia no color

Documentation

All the exported functions accept 2 parameters:

• colorString - any valid CSS color string
• returnRgb optional
  • if true, then an object containing RGB values is returned
  • if false or not passed, then a hex string is returned

blinder.protanomaly(colorString, returnRgb)

Part of the "Anomalous Trichromat" family of color blindness. The viewer sees low amounts of red.

Examples:

blinder.protanomaly("#42dead");
// result: "#9dcea5"
blinder.protanomaly("#42dead", false);
// result: "#9dcea5"
blinder.protanomaly("#42dead", true);
// result: {"R":156.81027381701807,"G":205.52274401697787,"B":164.8656701007824}

blinder.protanopia(colorString, returnRgb)

Part of the "Dichromat" family of color blindness. The viewer sees no red.

Examples:

blinder.protanopia("#42dead");
// result: "#d1c4a0"
blinder.protanopia("#42dead", false);
// result: "#d1c4a0"
blinder.protanopia("#42dead", true);
// result: {"R":208.70185885531413,"G":196.10716916953663,"B":160.21748158694382}

blinder.deuteranomaly(colorString, returnRgb)

Part of the "Anomalous Trichromat" family of color blindness. The viewer sees low amounts of green.

Examples:

blinder.deuteranomaly("#42dead");
// result: "#a5c9b3"
blinder.deuteranomaly("#42dead", false);
// result: "#a5c9b3"
blinder.deuteranomaly("#42dead", true);
// result: {"R":165.29136650372695,"G":201.41446893677266,"B":178.9125102904318}

blinder.deuteranopia(colorString, returnRgb)

Part of the "Dichromat" family of color blindness. The viewer sees no green.

Examples:

blinder.deuteranopia("#42dead");
// result: "#debeb6"
blinder.deuteranopia("#42dead", false);
// result: "#debeb6"
blinder.deuteranopia("#42dead", true);
// result: {"R":222.02929022014237,"G":189.6513083292142,"B":182.29108759925}

blinder.tritanomaly(colorString, returnRgb)

Part of the "Anomalous Trichromat" family of color blindness. The viewer sees low amounts of blue.

Examples:

blinder.tritanomaly("#42dead");
// result: "#56d8d1"
blinder.tritanomaly("#42dead", false);
// result: "#56d8d1"
blinder.tritanomaly("#42dead", true);
// result: {"R":86.14054005420464,"G":216.21898840123637,"B":209.23279525212993}

blinder.tritanopia(colorString, returnRgb)

Part of the "Dichromat" family of color blindness. The viewer sees no blue.

Examples:

blinder.tritanopia("#42dead");
// result: "#62d5e6"
blinder.tritanopia("#42dead", false);
// result: "#62d5e6"
blinder.tritanopia("#42dead", true);
// result: {"R":97.64942008517872,"G":212.91555320194286,"B":229.93724968191844}

blinder.achromatomaly(colorString, returnRgb)

Part of the "Monochromat" family of color blindness. The viewer sees the absence of most color.

Examples:

blinder.achromatomaly("#42dead");
// result: "#8ec7b5"
blinder.achromatomaly("#42dead", false);
// result: "#8ec7b5"
blinder.achromatomaly("#42dead", true);
// result: {"R":141.91089545454545,"G":198.63816818181814,"B":180.81998636363636}

blinder.achromatopsia(colorString, returnRgb)

Part of the "Monochromat" family of color blindness. The viewer sees no color at all.

Examples:

blinder.achromatopsia("#42dead");
// result: "#b9b9b9"
blinder.achromatopsia("#42dead", false);
// result: "#b9b9b9"
blinder.achromatopsia("#42dead", true);
// result: {"R":185.28855,"G":185.28855,"B":185.28855}

Links

• Original Source
• Color Blind / Daltonize Bookmarklet
• Color Blind Bookmarklet

Release History

v0.1.0 - Released June 21, 2014

• initial release

License

Originally this project was licensed with:

Copyright (c) 2014 skratchdot
Licensed under the MIT license.

But the main algorithm is from code that included:

The Color Blindness Simulation function is
copyright (c) 2000-2001 by Matthew Wickline and the
Human-Computer Interaction Resource Network ( http://hcirn.com/ ).

It is used with the permission of Matthew Wickline and HCIRN,
and is freely available for non-commercial use. For commercial use, please
contact the Human-Computer Interaction Resource Network ( http://hcirn.com/ ).

I've included a note about HCIRN that was copied/edited from http://colorlab.wickline.org/colorblind/colorlab/engine.js:

HCIRN appears to no longer exist. This makes it impractical
for users to obtain permission from HCIRN in order to use
this file for commercial works. Instead:

This work is licensed under a
Creative Commons Attribution-ShareAlike 4.0 International License.
http://creativecommons.org/licenses/by-sa/4.0/

On 10/13/2022 the license needed to be updated to include CC-BY-SA-4.0.

For more information about this change, please see: #3

Sorry for any issues this has caused.