I tried to set a colour in CMYK Colour schema in Inkscape: C:70 M:10 Y:80 K:40, that's RAL 6010.
But Inkscape changes one value when i enter another value, so i cant set this concrete colour! I noticed this behavior with a couple of colours...

So what's the problem? Does anyone know a solution to this?

Regards, Michael

Inkscape uses the web standard SVG format, so it's not ideal for CMYK. Can you use an RGB colour value instead? Is this needed for print?

I tried a new Approach: i set the cmyk values (i only know these values of the desired colour) in photoshop
to get the rgb values of this particular colour.

Then i set these rgb values in inkscape to be able to use the desired colour.
The thing i do not understand is that the cmyk values in inkscape for these rgb values are after this C:50 M:0 Y:47 K:55 and in Photoshop C:70 M:10 Y:80 K:40 (the original values).

Is there no standardized conversion of these two schemas? And i do not understand why svg has problems with CMYK Colours?

The reason the CMYK colour values are different is Inkscape still doesn't fully support CMYK - there are ways to make Inkscape work for print by using scribus though. I'm not an expert on this program, perhaps someone can explain better if you're interested?

The other reason is that there is no specific 1:1 mapping between CMYK and RGB. The two occupy different colour spaces and the conversion will depend on the colour profile in use.

-Rob A>

Hmm okay i understand. Thank you very much so far!

Maybe someone can explain how far scribus can halp me in this case.

Regards,
Michael