superpose.polygon, panel.polygon and their colors

Hi Dieter:

I think the OP wanted both lines and shading; from your code I could get
the
shading but not the lines. This is what it took for me to get the lines
(note the type and col.line changes in xyplot() ):

xyplot(est ~ x | cond, group = grp, data = data, type = 'r',
 col = 'gray80', col.line = c('red', 'blue'),
 upper = data$upper,
 lower = data$lower,
 panel = function(x, y, ...){
    panel.superpose(x, y, panel.groups = 'panel.bands',...)
    panel.xyplot(x, y, ...)
   })

But this creates a new problem...the lines extend farther than the bands.