The depictr colour palettes — depictr

Colourblind-aware palettes shared by every depictr plot. The qualitative palette is based on the Okabe-Ito set (Okabe & Ito, 2008), a widely recommended categorical palette that stays distinguishable under the common forms of colour-vision deficiency, with the depictr brand blue leading. The sequential and diverging palettes are perceptually ordered single-hue and red-blue ramps.

Usage

depictr_palette(
  n = NULL,
  type = c("qualitative", "sequential", "diverging"),
  order = c("default", "contrast")
)

Arguments

n: Number of colours to return. If NULL (the default), the qualitative palette returns all of its base colours, the eight Okabe-Ito colours unless options(depictr.palette = ) supplies another set, and the sequential and diverging ramps return seven. For the qualitative palette an n larger than the available base colours is interpolated; the sequential and diverging palettes are ramps and accept any n. Interpolating the built-in qualitative palette beyond its eight base colours loses the colour-vision-deficiency guarantee and warns, so facet the groups or use the sequential ramp when many groups are needed.
type: Palette type: "qualitative" (categorical groups), "sequential" (ordered low-to-high) or "diverging" (a midpoint with two directions).
order: The order of the built-in qualitative palette: "default", or "contrast" for the contrast-first order described below. The ramps have an order of their own and refuse "contrast".

Value

A character vector of hex colour codes.

Details

The guarantee belongs to the eight Okabe-Ito colours themselves, not to any number of colours: past eight the qualitative palette has to interpolate between them, and the interpolated colours sit close enough together to fail the package's own colour-distance check. That case warns rather than handing back colours under a guarantee it cannot keep.

The qualitative palette can be overridden globally with options(depictr.palette = ) (see depictr_options()); when set, that custom palette replaces the built-in Okabe-Ito set and is interpolated when more colours are requested than it provides. The sequential and diverging ramps are unaffected.

The contrast-first order

In the default order the second colour is the orange (#e69f00), at 2.25:1 against white. Any figure on white whose colour tells two or more groups apart therefore fails the geometry_contrast row of check_figure(). No more than three of the eight colours pass every colour row of that audit together.

order = "contrast" puts those three first: the brand blue, the vermillion (#d55e00) and the reddish purple (#cc79a7), then the bluish green (#009e73) and the other four in their default order. Up to three groups then pass every colour row, contrast against white included. They stay at least 14.01 apart in CIEDE2000 under every vision type, 6.86 apart in lightness and 3.06:1 against white. Four groups keep 3:1 against white, but the bluish green and the vermillion are 3.31 apart in lightness, which fails greyscale_separability. Asking for more than four colours warns, since the fifth, the orange, falls below 3:1.

Under this order, the second group is drawn in the vermillion. That is also the accent (depictr_options()) that depictr uses for single highlights, such as the flagged points of outlier_plot() and the missing cells of missingness_map(). The default order is unchanged.

The order applies to the built-in palette alone. A palette set with depictr_options(palette = ) is the user's own, so it is returned in the order it was set, with a warning. That is also how to make the order the default for every later plot: depictr_options(palette = depictr_palette(order = "contrast")). The palette is then the user's own, so asking for more than four colours no longer warns. scale_colour_depictr() and scale_fill_depictr() take order for a single plot.

References

Okabe M, Ito K (2008). “Color Universal Design (CUD): How to make figures and presentations that are friendly to colorblind people.” https://jfly.uni-koeln.de/color/. Accessed 2026-06-14.

World Wide Web Consortium (2023). “Web Content Accessibility Guidelines (WCAG) 2.2.” W3C Recommendation, https://www.w3.org/TR/WCAG22/. Accessed 2026-08-18.

Examples

depictr_palette(3)
#> [1] "#005b96" "#e69f00" "#009e73"
depictr_palette(3, order = "contrast")
#> [1] "#005b96" "#d55e00" "#cc79a7"
depictr_palette(7, type = "sequential")
#> [1] "#E6EFF5" "#98BFDA" "#4A8FC0" "#2475AB" "#005B96" "#034678" "#08315A"
scales::show_col(depictr_palette())