# exam.cls package change grid color

I'd like to change the grid color in the exam.cls package. By default, it seems to be black (although in the documentation it says the default color is gray). Anyway, I would like to have a very light gray, but defining a new color doesn't seem to change anything.

Here's a MWE:

\documentclass[11pt]{exam}

\usepackage{color}
%\definecolor{GridColor}{gray}{0.8}
\definecolor{GridColor}{rgb}{0.75, 0.75, 0.75}

\begin{document}
\begin{questions}

\question[1] Schreibe unten hin was immer du willst.

\fillwithgrid{\stretch{1}}
\newpage

\end{questions}
\end{document}


Thanks in advance for any help!

As the manual states, you have to issue the \colorgrids macro right after \usepackage{color}.

\documentclass[11pt]{exam}

\usepackage{color}
\colorgrids
%\definecolor{GridColor}{gray}{0.8}
\definecolor{GridColor}{rgb}{0.75, 0.75, 0.75}

\begin{document}
\begin{questions}