VHA-branded continuous fill scale — scale_fill_vha

A sequential or diverging colorspace HCL ramp.

Usage

scale_fill_vha_c(
  palette = c("sequential", "diverging"),
  direction = 1,
  na.value = .brands$vha$na_color,
  guide = "colorbar",
  ...
)

Arguments

palette: One of "sequential" (default) or "diverging"
direction: For palette = "sequential", 1 (default) maps higher values to darker colors; -1 reverses so higher values are lighter. For palette = "diverging", 1 (default) maps low values toward the first arm and high values toward the second; -1 swaps which arm represents low vs. high.
na.value: Default color for NA values (#d6dbdb, VHA Light Gray)
guide: Legend representation for scale
...: Other arguments passed on to ggplot2::continuous_scale()

Value

A ggplot2::continuous_scale() object.

Diverging ramp is provisional

VHA's diverging ramp pairs Dark Turq against Yellow, the palette's only warm hue. Yellow's natural HCL lightness is too high to survive as a dark, saturated anchor, so that arm renders golden/olive rather than bright yellow — a sRGB gamut limit, not a tuning slip. Still monotonic and distinguishable under protanopia/deuteranopia/tritanopia simulation, but — like HDA's diverging ramp — a candidate for a follow-up Ramp Lab pass (plans/DECISIONS.md).

Examples

library(ggplot2)
ggplot(mtcars, aes(wt, mpg, fill = disp)) +
  geom_point(shape = 21) +
  scale_fill_vha_c()