If I try to plot using change(stroked|filled) or
change(symbol) and provide only one item to plot,
things work out normally.
So I expected the same when using color.palette.XXX.
The primary use of palette is for more than one dataset
but as people start plotting things automatically with
scripts (as I do), it may happen at times that the
script will have only one dataset to plot, so it would
be nice if it simpled worked with a single data set as
If crashing with 1 data set is the intended behaviour,
I think I would be beter to define a new exception type
to give the user a beter hint of what went wrong.