Sometimes it's good to actually see the colour palette in an image rather than as a vector of character strings, especially when those strings are hex codes. Especially if, like me, you tend to change colour palettes depending on what type of plot or map you're making.

The following function uses the legend() function to display the colour palette with their colour names/strings. It tries to scale the legend to fit the number of colours in the palette. The only output is a blank plot showing just the legend.

showpal <- function(
    ncol = 2,
    cex=1.4,
    pt.cex=4
)
  {  lp0 <- length(palette())
  xspac <- pt.cex/5
  yspac <- 2*(pt.cex/5)
  if(lp0>12&ncol==2) {        # trying to fit longer palettes - needs work
    ncol <- ceiling(lp0/6)
    cex <- 24/lp0
    pt.cex <- 72/lp0
    xspac <- pt.cex/2
    yspac <- 1.25*(pt.cex/2.5)
  }
  par(mar=rep(0.5,4))
  plot(c(0,1),c(0,1), type="n", bty="n", ann = F, 
       xaxt="n", yaxt="n", xlab="", ylab="")
  legend("center", ncol = ncol, bty = "n", 
         legend=paste(paste0(seq(1,length(palette())),"."),
                                        palette()),
         title = "Current colour palette",
         pt.bg = seq(1,length(palette())), 
         pch = 22, 
         pt.cex = pt.cex, 
         cex = cex,
         x.intersp = xspac,
         y.intersp = yspac)
  par(mar = c(4,4,3,1))
}

Using the showpal() function

palette(c("black",rainbow(14, v=0.8, end=0.8),"gray64","white","transparent"))
showpal()

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