That's currently not possible, sorry.
For my purpose will be CMYK gamut better for printing colors. Some people choose colors which are not printable in CMYK printers (fluorescent colors).
Would be great, if this could work, so as a cmyk-colored PDF.
XONIC-SOLUTIONS
How can I use the color in CMYK-Value, instead of hex-Value?
(We have a print-customer and he needs CMYK-Values. )