[thelist] The use of color (was site header and logo)

[Heather Quinn]

By complement, I assume you are using the technical term meaning an 
opposing color, and that you don't mean "complimentary", or a 
harmonizing, color.  

My seat-ot-the-pants approach to getting a perfect complement is to take 
the color I want to create a complement for and reverse the three RGB 
values.  If pure blue's RGB triplet values are 0/0/255, my method 
calculates its complement as 255/0/0.  This is yellow, which is the 
correct complement of pure blue in the RGB light-based system.  

This approach takes the RGB value triplet, and subtracts each of the 3 
values from 255, then  uses each remainder to replace each of the three 
original values.  So a golden color that's  204/153/51 would have a 
complement of 51/102/204, which is a warm blue.  I think the reason this 
seems to work visually is that in light-based color, there's a maximum 
amount of light that can be distributed across the three color channels, 
and my little trick does a "negative" redistribution of light across 
each channel, which keeps the total light value the same, but flips the 
color balance.  This may be technically incorrect, but the resulting 
values look complementary to me, in that they vibrate against each 
other. They are also the same colors that result if, in PS, you do a 
color fill, select it, then do Image, Adjust, Invert.  

But if I'm giving out misinformation, I hope someone will chime in to 
correct me.

Alliax wrote:

>Heather, I too, am interested in the use of colors, even if I haven't much
>theory to base myself on.
>In my sites I tend to use randomness to choose colorization
>I choose randomly the base color, then I change the luminosity for others
>gradients.
>
>I'd like to know a simple algorythm to pass from an RGB value
>R = 0-255
>G = 0-255
>V = 0-255
>to its complementary color.
>
>I've read somewhere that I should transform RGB into HSV and then make some
>angles rotation and then convert back to RGB.
>I have no idea what HSV is yet, but would you know of a simple way of
>obtaining the complementary color from a RGB color ?
>
>my site which uses dynamic colorization the most is
>http://www.toulonparadise.com it's in french but it's secondary in this
>matter.
>
>Cordialement,
>
>__ Alliax         ~CV : http://LingoParadise.com/cv.php
>Un site pour Toulon : http://www.ToulonParadise.com
>Un site pour Renaud : http://www.rfaucilhon.com
>Un site pour Director : http://www.LingoParadise.com
>http://lists.evolt.org Workers of the Web, evolt !
>
>
>

-- 
Cheers,

Heather Quinn
info at windyhilldesign.com
http://www.windyhilldesign.com
hgquinn at attglobal.net
http://pws.prserv.net/windyhill