I tried to get a random color with xcolor and tikz:
\documentclass{article}
\usepackage[xetex, rgb]{xcolor}
\usepackage{tikz}
\begin{document}
\pgfmathsetseed{1}
\begin{tikzpicture}
\xdefinecolor{MyColor}{hsb}{rand, 1.0, 1.0}
\node[fill=MyColor]{Hello};
\end{tikzpicture}
\end{document}
But this does not work, it reports the following error
Missing number, treated as zero
Does anybody know how to get random colors? thanks.