\def\onecol{red}
\def\twocol{green}
\def\threecol{lightblue}

\renewcommand{\tdx}{0.5} % depth of 3d
\renewcommand{\tdy}{4}
%------------------------------------------------------------------
   %this is the way to redefine styles
   % \newpsstyle{mytickstyle}{linewidth=1pt,linecolor=blue}
   %
   \newpsstyle{diagframestyle}{linewidth=1pt,linecolor=black,fillcolor=white}
   \bardiagrambegin{13}{100}{3cm}{2}{7}{1cm}{0.1cm}
      \baritem{1990}{72}{\onecol}
       \subbaritem{2000}{50}{\twocol}
       \subbaritem{2010}{63}{\threecol}
      \baritem{1990}{81}{\onecol}
        \subbaritem{2000}{99}{\twocol}
        \subbaritem{2010}{50}{\threecol}
%        \baritemCYL{1990}{41}{\onecol}
%         \subbaritemTD{2000}{30}{\twocol}
%         \subbaritemTD{2010}{21}{\threecol}
   %\drawlevellines
   \bardiagramend
     {\parbox{14cm}{\vspace{-1.5cm}\hspace{-0.7cm}
         \begin{tabular}{p{7cm}p{6cm}}
           \centering Alpha's & \centering Beta's
         \end{tabular}
         \\[0.6cm]
         \centering \large Year}}
     {\large Graduated (\%)}