nColor — A Color Picker
What is it?
The nColor color picker allows to select and compare colors in various simulations of color-blind vision. This is a simple
HTML page with a JavaScript script and style properties. This page
should work on most browsers, unless script and stylesheet interpretation have been deactivated.
How does it work?
The easy way is to try current version of nColor.
Instructions for use are included in the page.
What if I want a copy?
Just save the page on your hard disk and use it as you wish.
Besides
Did you know that colorblindness is affecting 8 % of men and 0.4 % of women of Caucasian type ? Colorblindness is a generic term which covers
different types of visual deficiencies related to perception of red, green and blue components of color.
Some perceive all 3 parts but with weaknesses in some area of the light spectrum, the trichromats, others simply do not perceive
one part, the dichromats. The following table lists specific anomalies within these main categories.
Repartition of some visual anomalies
| |
trichromats |
dichromats |
deficiency |
100 % |
| protanopes |
1.0 % |
1.0 % |
red |
25 |
| deuteranopes |
4.9 % |
1.1 % |
green |
75 |
| tritanopes |
n/a |
0.002 % |
blue |
0.0 |
| achromatopes |
n/a |
0.003 % |
all |
0.0 |
We can see that most deficiencies occur in the red-green range. As a consequence, Web designers might be well inspired to check
that the color set of their pages remains acceptable at least to protanopes and deuteranopes.
Acknowledgments: This short introduction is an interpretation of Christine Rigden's
work.
The different nColor visual emulations are based on her work.
History
- version 2.1 - 2005-08-11:
added a function for checking readability based on a
W3C algorithm.
It is not 100 % full-proof, as Giordano Beretta explains,
but we'll keep it until better. When you move the cursor over the color grid, background of (B)lock and (T)ext controls would get darker,
if the background/text contrast might compromise text readability. Again, this algorithm is not completely reliable, particularly for
a blue text over an orange background.
- version 2.0 (new version numbering) - 2005-07-29 :
script revamped for better usability, in particular by improving color-blind vision switching and adding accesskey-like behavior to controls.
Layout doesn't use images anymore and scales automatically according to window width.
- version 8.0 - 2000-12-17:
improved user interface and better support for Netscape 6.x - Mozilla 0.6
- version 7.0 - 2000-12-07:
compatible with Netscape 6.x and Mozilla m18. Some minor modifications.
- version 6.0 - 2000-11-06:
automatic palet configuration according to browser window size.
- version 5.0 - 2000-10-24:
added funtions to simulate some visual deficiencies (colorblindness), code cleaning.
- version 4.0 - 2000-06-12:
three-color comparizon (background, block and text).
- version 3.0 - 2000-04-19:
reordered palet around 6 color families: blue, magenta, red, yellow, green, cyan
- versions 1.0 and 2.0 - 2000-01-01:
first online versions, two-color comparizon (background and text)
