\input{preamble-standalone.ltx}
\begin{document}

% Ex. No. 65 (Section  8.6.2 : Changing the style)

\begin{tikzpicture}
   \tikzset{point style/.style={%
     draw         = blue,
     inner sep    = 0pt,
     shape        = circle,
     minimum size = 6pt,
     fill         = red!20}}
   \tkzDefPoint(1,3){A}
   \tkzDefPoint(4,1){B}
   \tkzDefPoint(0,0){O}
   \tkzDrawPoint(A)
   \tkzDrawPoint(B)
   \tkzDrawPoint(O)
\end{tikzpicture}

\end{document}