R color to RGB (red/green/blue) conversion.
col2hex(cname, alpha = FALSE)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].
logical value indicating whether the alpha channel (opacity) values should be returned.