On Jun 11, 2010, at 5:09 PM, John Culleton wrote:
Given that internally Inkscape is still using the RGB color model I wonder if this is a color that will actually be used for output.
It does... but doesn't quite have to.
If you set a true CMYK color, then it stays as 4 values.
There are several swatch bars available but none seem to be expressed in CMYK terms.
"CMYK" in and of itself is meaningless as far as defining color goes. "RGB" is also fairly meaningless, but the good news is that SVG specifies that it does all base colors in "sRGB", and not just random "RGB".
To get control of color, you need to specify an ICC color profile that states exactly what visual result the random numeric input results in. There are a few 'standard' CMYK profiles that are similar to the 'standard' "sRGB" color profile.
So... just reference one (or more) ICC color profiles in your SVG document and then the "CMS" picker (and to some degree the others) will let you specify colors in *true* CMYK values... and ones that Scibus can even import.
If in fact all possible CMYK colors can be expressed in RGB terms then it should be possible to use pseudo CMYK colors on the Inkscape color bar and pass these shades on to e.g., Scribus in RGB format. I would be interested in comments from the developers on this.
No, it's not possible to express all CMYK colors in RGB terms, at least not with the numeric limits used in SVG.
if you're interested in more details, you can get the slides and watch a video of my presentation on this at linux.conf.au 2009. http://codewideopen.blogspot.com/2009/02/color-talk-at-linuxconfau.html