We used tcolorbox with gradient shade with single color that is gray to white percentages, we checked the output in PDF the color showing CMYK mixed color, is my TeX coding correct?

\documentclass{book}
\usepackage{tcolorbox}
\tcbuselibrary{skins}

\makeatletter%
\pagestyle{empty}
enhanced,boxrule=0pt,boxsep=0pt,sharp corners,
#1
}
\makeatother%

\begin{document}