Recycle colors in a palette when exceeding the maximum number of defined colors

[MikkoVihtakari]

Is there an easy way of changing the default behavior of scales palette functions to repeat colors when running out of defined alternatives instead of returning NAs? I am looking for something similar to grDevides::palette.colors(..., recycle = TRUE). This would come in handy when passing manual colors to ggplot2 as there are more predefined palettes in the scales package than in grDevices.

library(scales)

## Works in grDevices

grDevices::palette.colors(20, palette = "Set 1", recycle = TRUE)
#>  [1] "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00" "#FFFF33" "#A65628"
#>  [8] "#F781BF" "#999999" "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00"
#> [15] "#FFFF33" "#A65628" "#F781BF" "#999999" "#E41A1C" "#377EB8"

## My clumsy approach for scales palettes
color_palette <- scales::brewer_pal(palette = "Set1")

color_palette(5)
#> [1] "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00"
color_palette(20)
#> Warning in RColorBrewer::brewer.pal(n, pal): n too large, allowed maximum for palette Set1 is 9
#> Returning the palette you asked for with that many colors
#>  [1] "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00" "#FFFF33" "#A65628"
#>  [8] "#F781BF" "#999999" NA        NA        NA        NA        NA       
#> [15] NA        NA        NA        NA        NA        NA

repeat_palette <- function(n, pal = color_palette) {
  if(inherits(
      tryCatch(pal(n), error=function(e) e, warning=function(w) w),
    "character")
    ) {
    pal(n)
  } else {
    tmp <- suppressWarnings(pal(1e5))
    tmp <- tmp[!is.na(tmp)]
    rep(tmp, length.out = n)
  }
}

repeat_palette(20)
#>  [1] "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00" "#FFFF33" "#A65628"
#>  [8] "#F781BF" "#999999" "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00"
#> [15] "#FFFF33" "#A65628" "#F781BF" "#999999" "#E41A1C" "#377EB8"
repeat_palette(5)
#> [1] "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00"

scales::show_col(repeat_palette(20))

^{Created on 2022-12-05 with reprex v2.0.2}

[thomasp85]

This is not planned. In general the palette behaviour is made intentional so as to ensure that the input data works with the palette