[Javascript] OT: Why 51?

[Roger Roelofs]

Shawn,

On Aug 5, 2004, at 8:00 AM, shawn_milochik at godivachoc.com wrote:

> On the site you listed below, there is a "216 safe web colors" link.  I
> clicked on it out of curiosity.
> http://www.web-source.net/216_color_chart.htm
>
> I have two questions:
>
> 1.  Why are only 216 colors "safe," and not just any valid hex or RGB
> within range?
>
> 2.  I noticed that the values used for R, G, and B were: 255, 204, 153,
> 102, 51, and 0
> Those are, apparently, the only "safe" RGB values.  I noticed that the
> increment
> there is 51.  What is the significance?
>
> I know this is a bit off-topic, but I'm not a member of the "web 
> trivia"
> mailing list.  ;o)
>
Back at the dawn of time, many computers could only display 256 colors, 
and if you chose a color it couldn't display it would dither to try to 
come close, often with disasterous results... Thats why the 216 colors 
were referred to as 'safe'  :)  There were only 216 because of some 
variance between browsers and platforms.  Back then, software used 
'palletes' to map color values to screen pixels.

In hex, the numbers are 00 33 66 99 cc ff, which makes more sense to 
programmers than designers.  For an article about all this, try 
<http://www.lynda.com/hex.html>


Roger
-------------------------------------------------------
Roger Roelofs                 web   www.datacompusa.com
Datacomp Appraisal Services   web   www.mhvillage.com
3215 Eaglecrest Drive, NE     Email rer at datacompusa.com
Grand Rapids, MI  49525-4593