Generate N Colors from a Specified Color Palette

A flexible wrapper around multiple color palette libraries, returning N colors as a character vector of hex codes. Supports palettes from viridisLite, base R grDevices, and RColorBrewer.

Usage

generate_colors(n, palette = "viridis", ...)

Arguments

n

integer. Number of colors to generate. Must be a positive integer.

palette

character(1). Name of the color palette to use. Case-insensitive. Supported options:

viridisLite

"viridis", "magma", "plasma", "inferno", "cividis", "mako", "rocket", "turbo"

grDevices

"hcl", "rainbow", "heat", "terrain", "topo"

RColorBrewer

Any palette name from RColorBrewer::brewer.pal.info, e.g. "Set1", "Blues", "Dark2". If n exceeds the palette maximum, colors are interpolated via colorRampPalette.

...

Additional arguments passed to the underlying palette function. For example, alpha, direction, begin, end are forwarded to viridis; palette is forwarded to hcl.colors.

Value

A character vector of length n containing hex color codes (e.g. "#440154FF").

See also

viridis, hcl.colors, brewer.pal

Examples

# viridisLite palettes
generate_colors(5, "viridis")
#> [1] "#440154FF" "#3B528BFF" "#21908CFF" "#5DC863FF" "#FDE725FF"
generate_colors(5, "plasma")
#> [1] "#0D0887FF" "#7E03A8FF" "#CC4678FF" "#F89441FF" "#F0F921FF"
generate_colors(5, "viridis", alpha = 0.8, direction = -1)
#> [1] "#FDE725CC" "#5DC863CC" "#21908CCC" "#3B528BCC" "#440154CC"

# Base R grDevices
generate_colors(5, "rainbow")
#> [1] "#FF0000" "#CCFF00" "#00FF66" "#0066FF" "#CC00FF"
generate_colors(8, "hcl", palette = "Dark 3")
#> Warning: NAs introduced by coercion
#> [1] "#E16A86FF" "#C7821CFF" "#909800FF" "#00A846FF" "#00AD9AFF" "#00A2D3FF"
#> [7] "#9183E6FF" "#D766C9FF"

# RColorBrewer
generate_colors(5, "Set1")
#> [1] "#E41A1C" "#377EB8" "#4DAF4A" "#984EA3" "#FF7F00"
generate_colors(5, "Blues")
#> [1] "#EFF3FF" "#BDD7E7" "#6BAED6" "#3182BD" "#08519C"
generate_colors(12, "Set1")  # interpolates beyond palette max of 9
#>  [1] "#E41A1C" "#66628D" "#419486" "#5A9D5A" "#91569A" "#D96D3B" "#FFAD12"
#>  [8] "#F6EF32" "#B6742A" "#D26D7A" "#DD87B4" "#999999"

# Drop-in replacement for viridisLite::viridis()
# generate_colors(n = length(levels(data_orig[[pri]])), palette = "viridis")