Color palettes where every color has a paper behind it.

Named after entoptic phenomena — visual experiences generated within the eye itself, such as Haidinger's brushes and Eigengrau, both of which appear in this package.

devtools::install_github("thhaase/entoptic")

The dark pole is Eigengrau (#16161D, L*≈5): the color your visual cortex generates in total absence of light, caused by spontaneous retinal neuron firing.

Barlow, H.B. (1956). Retinal noise and absolute threshold. Journal of the Optical Society of America, 46(8), 634–639. Baylor, D.A., Lamb, T.D., & Yau, K.W. (1979). Responses of retinal rods to single photons. Journal of Physiology, 288, 613–634.

The light pole is CMB Beige (#FFEFD5, L*≈95): the color of the Cosmic Microwave Background — the oldest light in the observable universe, the 2.725 K blackbody radiation released ~380,000 years after the Big Bang, first detected by Penzias & Wilson and later mapped across the full sky.

Penzias, A.A. & Wilson, R.W. (1965). A measurement of excess antenna temperature at 4080 Mc/s. The Astrophysical Journal, 142, 419–421. Bennett, C.L., et al. (2003). First-year WMAP observations. The Astrophysical Journal Supplement, 148(1), 1–27. Planck Collaboration (2020). Planck 2018 results I. Astronomy & Astrophysics, 641, A1. Glazebrook, K. & Baldry, I. (2002). The 2dF Galaxy Redshift Survey. The Astrophysical Journal, 571(1), 169–186.

Anchored on Hospital Green (#5B8C5A), sweeping from dark teal to warm parchment. The anchor color is grounded in the same surgical science as the Science palette:

Sherman, H.M. (1914). California State Journal of Medicine, 12(5), 181–183.

A vertical cross-section through an open wound, from deep necrotic tissue to the surface fat layer:

The temporal color cascade of hemoglobin degradation during wound healing. Each anchor maps to a biochemically distinct pigment stage in chronological order:

library(entoptic)

# Generate n colors
entoptic(5, option = "science")
entoptic(256, option = "firstlight")

# Convenience functions
science(5)
understorey(9)
firstlight(256)
openwound(7)    # or open_wound(7)
hemolysis(7)

# Plots
image(volcano, col = firstlight(256))
filled.contour(volcano, color.palette = understorey)
barplot(1:5, col = science(5))
heatmap(as.matrix(mtcars), col = openwound(64))
heatmap(as.matrix(mtcars), col = hemolysis(64))

# Preview
entoptic_show("open_wound")
entoptic_show("hemolysis")

# Reverse & subset
firstlight(10, direction = -1)
entoptic(7, option = "hemolysis", begin = 0.2, end = 0.8)

library(ggplot2)
library(entoptic)

# ── Continuous ──────────────────
ggplot(faithfuld, aes(waiting, eruptions, fill = density)) +
  geom_tile() +
  scale_fill_entoptic_c(option = "firstlight")

ggplot(iris, aes(Sepal.Length, Sepal.Width, colour = Petal.Length)) +
  geom_point(size = 3) +
  scale_colour_entoptic_c(option = "understorey")

# ── Discrete ────────────────────
ggplot(mpg, aes(displ, hwy, colour = class)) +
  geom_point(size = 2) +
  scale_colour_entoptic_d(option = "science")

ggplot(mpg, aes(class, fill = class)) +
  geom_bar() +
  scale_fill_entoptic_d(option = "science")

# ── Binned ──────────────────────
ggplot(iris, aes(Sepal.Length, Sepal.Width, colour = Petal.Length)) +
  geom_point(size = 3) +
  scale_colour_entoptic_b(option = "firstlight")

All scale_colour_* have scale_color_* aliases.

All palette functions accept: