[R] Background color(s) for groupedData plot

[Paul, David A]

I've been using par() to check the graphics parameters
associated with both plot(<fitted linear model>) and
plot(<grouped data object>).  AFAIK the only differences
are in the $cxy, $usr, $xaxp, and $yaxp parameters but
the background color for the grouped data plot is grey
while the linear model plot has a white background.

When I've tried par(bg = "white") prior to using the
plot(<grouped data object>) command it doesn't seem to make any
difference.

How can I change the grey background to something else?


Much thanks in advance,
  David Paul