[Scribus] cmyk vs rgb

[Hal V. Engel]

On Tuesday 24 April 2007 04:59, Farid Elyahyaoui wrote:
snip
> Now I switched on color management:
> settings:
> RGB pictures: sRGB IEC61966-2.1
> CMYK pictures: ISO Coated
> Solid colors:  sRGB IEC61966-2.1
> Monitor: sRGB IEC61966-2.1 (don't have a monitor profile)

You might try using LProf's rough monitor profiler.  It will at least allow 
you to get the gamma of the RGB channels correctly set in the profile. This 
will be a modest improvement over using the sRGB profile.

> Printer: ISO Coated
>
> Rendering intents:
> Monitor: Relative Colorimetric
> Printer: Perceptual
> Simulate Printer (checked)
> Use blackpoint compensation (checked)
>
> PDF output settings:
> Color tab
> Solid colors:
>    use ICC Profile (checked)
>    Profile: sRGB IEC61966-2.1
>    intent: Relative Colorimetric
> Images:
>   Don't use embedded ICC profiles (checked)
>   Profile: sRGB IEC61966-2.1
>   Rendering intent: Relative Colorimetric
>
> PDF X/3 tab:
>  Output profile: ISO Coated
>
> The solid colors in scribus with the 'simulate printer on screen' on
> for some reason still look greyish.
> BUT:
> If I now open the pdf in acroread It looks OK (no dark/grayish colors
> anymore). Am I now on to something? Would this be OK to send to the printer
> now?
>
> Old post:
> --------------------------------------------------------------
> ---------------------------------
>
> > I'm still trying to grasp the color management settings in scribus
> > (and color management in general). I understand that RGB and CMYK are
> > completely different color spaces. What I fail to understand is the
> > following though:
> > If I load a RGB jpeg into scribus and output a cmyk pdf and view the
> > pdf on the same machine with acrobat reader the colors look greyish. I
> > understand that I need color management to get matching colors between
> > screen and what gets printed on paper.
> >
> > BUT (!) why do I get the different colors if I only work on one
> > monitor on one machine?
> >
> > One would expect that if scribus calculates RGB->CMYK and acrobat
> > displays these CMYK colors on the monitor (using RGB of course) that
> > the colors would be the same. that is if the calculations are the
> > inverse of each other. Or am I completely wrong here?
>
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