[CREATE] Color swatches

[Kai-Uwe Behrmann]

Am 06.04.08, 17:16 +0200 schrieb Olivier BERTEN:

> Now some thoughts about color swatches in general and about the CREATE draft:
> 
> 
> Registration color

What does Registration mean?
 
> IMHO, this shouldn't come in a color swatch file. It's a "system" color, just
> the opposite of 'None'. It depends of the colors used in the document. If
> you're using only cyan in your document, registration will be 100% cyan. If
> your document contains only magenta and yellow, registration will be red. And

Seems Cmyk is ignored this way.

> if you have spot colors, registration won't be C=100% M=100% Y=100% K=100%. In
> other words, registration can't be defined out of the document's context.
> Registration should just be added in the software's color list for any press
> work.

?? 
 
> Color swatch draft
> <http://create.freedesktop.org/wiki/index.php/Swatches_-_colour_file_format/Draft>
> 
> The name and space attributes shouldn't be mandatory. A color doesn't need a
> name to come into a palette and many palettes are just a arbitrary
> "geometrical" division of the possibilities of color model. When you have

Just numerical kind of colours are not precise.

> #003399 in a palette, it's not because it looks like anything in real life,
> it's just because its neighbors are #003366 and #0033CC. It just shows
> different possibilities of RGB, whether you're using sRGB or AdobeRGB doesn't

It would be nice in having a reference to colour spaces.

> matter. The same applies to "Black 20%" (or C=10% M=20% Y=30% K%). There are a
> lot of such palettes where neither the name or the color space have any
> importance. By the way, Lab and XYZ don't need any color space since these are
> device-independant models.

Lab and XYZ need a colorimetric reference, in ICC context to white, in a 
more general context viewing conditions and physical intensities.

kind regards
Kai-Uwe Behrmann
-- 
developing for colour management 
www.behrmann.name + www.oyranos.org