Make a color less bright a.k.a. pseudo-transparent

xcolor color

Source

• https://ctan.mirror.norbert-ruehl.de/macros/latex/contrib/xcolor/xcolor.pdf

\usepackage[svgnames]{xcolor}
 
\begin{document}
    Normal cyan: \color{Cyan}\\
    Very light cyan: \color{Cyan!20}
\end{dpcument}