hex to Lab color space & Lab color space to hex.

hextolab.R

hex_to_Labspace <- function(hex) { 
  hextolab <- function(x)
    convertColor(x,from="sRGB",to="Lab")
  rgb_col <- col2rgb(hex)/255
  labspace <- apply(rgb_col, 2, hextolab) %>% t
  colnames(labspace) <- c('L','a','b')
  return(labspace)
}

Labspace_to_hex <- function(lab) {
  labtohex <- function(x) {
    rgb_space <- convertColor(x,from="Lab",
                              to="sRGB")
    r <- rgb_space[1,1]
    g <- rgb_space[1,2]
    b <- rgb_space[1,3]
    rgb(r, g, b, maxColorValue = 1)
  }
  return(apply(lab, 1, labtohex))
}

# example 

colors <- c("#FFBEB2", "#AE123A")
labcol <- hex_to_Labspace(colors)
identical(Labspace_to_hex(labcol),colors)