How can I use the maroon that I have defined, instead of the gray? Or (better) how can I use directly the maroon from:
\usepackage[dvipsnames]{xcolor}
\documentclass{scrbook}
\usepackage{colortbl}
\definecolor{maroon}{cmyk}{0,0.87,0.68,0.32}
\newcommand{\gray}{\rowcolor[gray]{.90}}
\begin{document}
\begin{tabular}{|l|c|}
\rowcolor[gray]{.9}
one&two\\
\rowcolor[gray]{.5}
three&four
\end{tabular}
\end{document}
For an existing color or one previously defined using \definecolor or \colorlet, you can use \rowcolor{maroon}; if you need shades of the color, you can use the !<value> syntax provided by xcolor (the table option for xcolor internally loads colortbl):
\documentclass{scrbook}
\usepackage[table]{xcolor}
\definecolor{maroon}{cmyk}{0,0.87,0.68,0.32}
\begin{document}
\noindent\begin{tabular}{|l|c|}
\rowcolor{maroon}
one & two \\
\rowcolor{maroon!50}
three & four \\
\rowcolor{maroon!10}
five & six
\end{tabular}
\end{document}
Similarly for the Maroon color already provided by the dvipsnames option:
\documentclass{scrbook}
\usepackage[table,dvipsnames]{xcolor}
\begin{document}
\noindent\begin{tabular}{|l|c|}
\rowcolor{Maroon}
one & two \\
\rowcolor{Maroon!50}
three & four \\
\rowcolor{Maroon!10}
five & six
\end{tabular}
\end{document}
The first optional argument for \rowcolor (or \columncolor, or \cellcolor) behaves like the optional argument for \color:
\color[<model>]{<color specification>}
If the optional argument is used, then the mandatory argument expects a <colour specification> instead of a <name>.
For a list of available color models (using xcolor), see Section 2.2 of the xcolor documentation.
\rowcolor{maroon}– David Carlisle May 05 '13 at 21:14\rowcolor{maroon}. The optional argument of\color(or\rowcolor) is a color model and if used then the mandatory argumnet takes a color syntax in that model so the[gray]model takes a single number. If you don't use the optional argument then it's a color name as defined by\definecolor– David Carlisle May 05 '13 at 21:26