color.cfg
% https://creativecommons.org/publicdomain/zero/1.0/
\ProvidesFile{color.cfg}%
[2016/01/02 v1.6 sample color configuration]
% Select an appropriate default driver
\begingroup
\chardef\x=0\relax
% check luatex
\ifx\luatexversion\@undefined
% check pdfTeX
\@ifundefined{pdfoutput}{}{%
\ifnum\pdfoutput<1 %
\else
\chardef\x=1\relax
\fi
}%
% check VTeX
\@ifundefined{OpMode}{}{%
\chardef\x=2\relax
}%
% check XeTeX
\@ifundefined{XeTeXversion}{}{%
\chardef\x=3\relax
}%
\else
\ifnum\luatexversion>85
\ifnum\outputmode>0
\chardef\x=4\relax
\fi
\else
\ifnum\pdfoutput>0
\chardef\x=1\relax
\fi
\fi
\fi
\expandafter\endgroup
\ifcase\x
% default case
\def\Gin@driver{dvips.def}%
\ExecuteOptions{dvips}%
\or
% pdfTeX is running in pdf mode
\def\Gin@driver{pdftex.def}%
\ExecuteOptions{pdftex}%
\or
% VTeX is running
\def\Gin@driver{vtex.def}%
\ExecuteOptions{vtex}%
\or
% XeTeX is running
\def\Gin@driver{xetex.def}%
\ExecuteOptions{xetex}%
\or
% luatex (> 0.85)
\def\Gin@driver{luatex.def}%
\ExecuteOptions{luatex}%
\else
\PackageError{color}{Unexpected configuration}{}
\fi
\endinput