Prevent xcolor from putting B/W pages to cmyk color space

Question

I'm using xcolor for color support within my project. When compiling the files to pdf, I obtain a file whose entirety of pages is in the color space DeviceCMYK, even the black and white ones -- seems to be intuitive, but let's my copy shop count all pages as colored pages. However, black is properly defined.

MWE:

\documentclass{letter}
\usepackage[cmyk]{xcolor}
\begin{document}
    Test
\end{document}

Checking the color coverage on the page (gs -o - -sDEVICE=inkcov test.pdf; props to in Kurt Pfeifle his post) gives:

Page 1
 0.00000  0.00000  0.00000  0.00009 CMYK OK

Desired behavior: I would wish for all pages, where the coverage of C, M and Y is 0.0, being in the color space DeviceGray or comparable (not being in CMYK color space). As my document sums up to approx. 180 pages, I would like to come around slicing and manual conversion of pages.

Questions:

Does this issue occur because of the color re-definition, that Joseph Wright mentions in his post?
Is there any way to achieve my desired behavior?

The [cmyk] option for xcolor explicitly requests that all colors get converted to CMYK. If you don't want that, just don't pass that option. — Marcel Krüger, Oct 04 '21 at 11:50
Wow, how obvious... Thanks and sorry for that silly mistake... — Chris, Oct 04 '21 at 11:59

score 1 · Answer 1 · answered Oct 04 '21 at 12:01

1

As stated by Marcel Krüger -- Just do not ask what you do not like: Don't pass [cmyk] as that converts all colors.

answered Oct 04 '21 at 12:01

Chris

185

Prevent xcolor from putting B/W pages to cmyk color space

1 Answers1