Chess Notation with skak: How to highlight squares?

i'm using the skak-package for some chess notation in a presentation. My only issue: How can i highlight various squares on the chessboard? Basic:

\documentclass[12pt]{beamer}
\usepackage{skak}

\begin{document}
\begin{frame}
\newgame
\fenboard{8/8/8/3Q4/8/8/8/8 w - - 0 0} % FEN-notation, only one Queen
\showboard
\end{frame}
\end{document}

For example, i want to show the possible movements for a Queen on the board. I've tried the \highlight{} command (see below), but it throws errors.

\documentclass[12pt]{beamer}
\usepackage{skak}

\begin{document}
\begin{frame}
\newgame
\fenboard{8/8/8/3Q4/8/8/8/8 w - - 0 0} % FEN-notation, only one Queen
\showboard
\highlight{d4,d6}
\end{frame}
\end{document}

Shown Error: !Undefined control sequence. <recently read> \c@lor@to@ps l.49 \end{frame}. I use Texmaker with PdfLatex.

So, whats wrong?