alphacol adds an alpha value to a colour
specification and convert to a hexadecimal colour string.
Usage
alphacol(col, alpha = FALSE)
Arguments
col
vector of any of the three kinds of R color
specifications, i.e., either a color name (as listed by
colors()), a hexadecimal string of the form
"#rrggbb" or "#rrggbbaa" (see
rgb), or a positive integer i
meaning palette()[i].
alpha
logical value indicating whether the alpha
channel (opacity) values should be returned.