Get a Color Palette

Retrieve a named palette by name and type, returning a vector of HEX colors. Automatically checks for type mismatch and provides smart suggestions.

Usage

get_palette(name, type = NULL, n = NULL, reverse = FALSE, palettes_dir = NULL)

Arguments

name

Character. Name of the palette (e.g. "qual_vivid").

type

Character. One of "sequential", "diverging", "qualitative". If NULL, type is auto-detected.

n

Integer. Number of colors to return. If NULL, returns all colors. See What n means above. Default is NULL.

reverse

Logical. Reverse the palette before n is applied, so the two arguments stay independent: reverse hands back a different palette and n then selects from it. Default: FALSE.

palettes_dir

Character. Directory holding a palette collection (sequential/, diverging/, qualitative/ subdirectories of JSON files). If NULL, the palettes bundled with the package are used.

Value

Character vector of HEX color codes.

What n means

n is resolved according to what the palette's type says the colors are, because "give me 3 colors" means two different things:

qualitative

The colors are unordered categories, so n takes the first n of them. Asking for more than the palette holds is an error — there is no way to invent a category that the palette does not contain.

sequential, diverging

The colors are stops along a ramp, so n returns n steps spanning the whole ramp, interpolating as needed. Interpolation takes place in Lab colour space, matching the package's ggplot2 gradient scales. Any n works, above or below the number of stops. Taking the first n stops instead would silently hand back one end of the ramp — the light half of a sequential scale, or one arm of a diverging one.

n equal to the number of stops returns the palette untouched. When reverse = TRUE the palette is flipped first, so n selects from the reversed palette.

Examples

get_palette("gene_red", type = "qualitative")
#> [1] "#000000" "#B11522"

# Qualitative: the first n categories
get_palette("walter_white2", type = "qualitative", n = 2)
#> [1] "#5AB5BF" "#808C56"

# Sequential: n steps across the whole ramp, not the first n stops
get_palette("mitonuclear_blue")
#> [1] "#EEF4FB" "#DDF1F5" "#B9DBF4" "#95AAD3" "#3A68AE" "#155289"
get_palette("mitonuclear_blue", n = 3)
#> [1] "#EEF4FB" "#A7C2E3" "#155289"

# Ramps can also be stretched beyond the stops they were drawn from
get_palette("walter_white", type = "diverging", n = 9)
#> [1] "#1991A9" "#6DABB7" "#A3C5C4" "#C5D7D4" "#E7E9E4" "#C8CFB5" "#A9B688"
#> [8] "#788759" "#495A2E"

# Flip a ramp end to end
get_palette("mitonuclear_blue", reverse = TRUE)
#> [1] "#155289" "#3A68AE" "#95AAD3" "#B9DBF4" "#DDF1F5" "#EEF4FB"