Convert R colours and rgb values to hex

col2hex.R

col2hex <- function(colour) {
  col_rgb <- t(col2rgb(colour))
  rgb2hex(red = col_rgb[,1], green = col_rgb[,2], blue = col_rgb[,3])
}

rgb2hex <- function(red, green, blue, rgbvec = NULL) {
  
  if ((missing(red) || missing(green) || missing(blue)) && is.null(rgbvec)) {
    stop("You must supply red, green, and blue OR rgbvec")
  }
  
  if (!is.null(rgbvec)) {
    if (length(rgbvec) != 3) stop("rgbvec must be of length 3")
    red <- rgbvec[1]
    green <- rgbvec[2]
    blue <- rgbvec[3]
  }
  
  reds_hex <- tohex(red)
  greens_hex <- tohex(green)
  blues_hex <- tohex(blue)
  
  hexes <- paste0("#", reds_hex, greens_hex, blues_hex)
  
  hexes
    
}

tohex <- function(n) {
  
  if (!inherits(n, c("numeric", "integer"))) stop(" value is not numeric or integer")
  if (!(n <= 255 && n >= 0)) stop("value must be between 0 and 255 (inclusive)")
  
  format(as.hexmode(n), width = 2)

}