plot points with RGB color

Hi, I'm trying to plot a set of points using given RGB

    > tuples as color: plot([0.5],[0.5], '.', markersize=50,
    > color=(0.5,0.5,0.5)) there is no error but the point I got
    > is still blue. Any tips?

markers and lines have different property names.

  plot([0.5],[0.5], '.', markersize=50, markerfacecolor=(0.5,0.5,0.5))

the properties that control markers are markerfacecolor,
markeredgecolor and markeredgewidth, with abbreviations mfc, mec and