A character vector providing the colors to use in the plot.
font
A length-one numeric vector for the font to use for text.
Can be a vector. NA values (the default) mean use par("font").
cex.font
A length-one numeric vector for the character expansion
factor. NULL and NA are equivalent to 1.0. This is an
absolute measure, not scaled by par("cex") or by setting
' par("mfrow") or par("mfcol"). Can be a vector.