[MiKTeX] can not use prosper styles other than those come with miktex prosper

[Cosmos <je...@pu...>]

Hello there,

I use Miktex and prosper.cls to creat slides. I find I can only use those
prosper styles included in
Miktex dowload. If I use a style file (PPR*.sty) which I got from other
places, an error message
"----------------------------------------
!Latex Error Missing \begin{doccument}

see the LAtex manual ...
type H.....xxx

l.159  \definecolor{black}{gray}{0}
"-----------------------------------

will appear.

This line of command :"\definecolor{black}{gray}{0}",
is in file "color.sty" line 159 in "graphics" package.

What should I do to solve this problem?

JY