Xcolor Gray counts for colored pages (gray does not)

color

I noticed a strange difference between xcolor Gray and the standard gray.
I am currently preparing to print my thesis and (as often discussed in the forum), color pages are often much more expensive compared to black & white (BW).

So I switched my color setup for printing but the print service I am using (in this case: https://www.primydo.de) still counts pages with Gray as color pages. If I switch to gray instead, it works perfectly and the pages are recognized as BW.

I could request how they decide a page use colors. But since this is clearly TeX-related, I thought I should ask here first. Additionally, if someone runs into the same issue, it might be very beneficial to find an answer/explanation here.

MWE:

\documentclass{article}
\usepackage[dvipsnames,table]{xcolor}
\begin{document}
{\color{Gray} This page counts for colored pages.}

\pagebreak
{\color{gray} This page does NOT count for colored pages.}
\end{document}

Best Answer

The dvipsnames options loads named colours all of which are intended for classical printing: they are all CMYK (including Black and White). This contrasts with gray, which is defined using the gray model and thus is black-and-white.

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