Changed the default colour sheme to use a Black pen writing on a White background.  The remaining colours were reorganized to produce the best results with the suite of PLplot examples.
Changed the default colour sheme to use a Black pen writing on a
White background.  The remaining colours were reorganized to produce
the best results with the suite of PLplot examples.

svn path=/trunk/; revision=6213

FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot,FreeScienceCommunity/PLPlot