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Simulating how colours look to a colour-blind viewer

Source: R/theme_colorblind.R
theme_colorblind.Rd

simulate_colorblind() returns what a set of colours looks like to a viewer with a given type of colour vision deficiency (CVD), which affects about 8% of men and 0.5% of women, or in greyscale, as a reader sees the plot in print.

Usage

simulate_colorblind(
  colors,
  type = c("deutan", "protan", "tritan", "grey", "normal"),
  severity = 1
)

Arguments

colors

One or more colours, given as hexcodes or as names R knows.

type

The type of colour blindness to simulate: "deutan" (green-blind, the most common), "protan" (red-blind), "tritan" (blue-blind), "grey" for greyscale, as a photocopier renders it, or "normal" for unaffected vision.

severity

How severe the colour blindness is, between 0 and 1. By default 1, which is dichromacy. A value between 0 and 1 is anomalous trichromacy. Ignored for the "grey" and "normal" types.

Value

simulate_colorblind() returns a vector of hexcodes as long as colors.

Details

Simulation uses the matrices of Machado, Oliveira and Fernandes (2009), applied in linear RGB. Those matrices are published for each severity of colour blindness; severity interpolates between the identity and the full-severity matrix, which approximates the published steps closely enough for a check. Full severity is dichromacy (deuteranopia, protanopia, tritanopia); a lower severity is anomalous trichromacy (deuteranomaly, protanomaly), which is the more common condition. Greyscale conversion takes the relative luminance of the colour, the same quantity check_contrast() scores with.

References

Machado, Gustavo M., Manuel M. Oliveira, and Leandro A. F. Fernandes. 2009. "A Physiologically-Based Model for Simulation of Color Vision Deficiency". IEEE Transactions on Visualization and Computer Graphics 15(6): 1291-98. doi:10.1109/TVCG.2009.113

See also

check_colors(), which scores a palette rather than simulating it.

Other themes: check_colors, list_fonts(), theme_medium, theme_set

Examples

simulate_colorblind(c("#d73027", "#4575b4"), "deutan")
#> [1] "#8E7F1E" "#4B6FB3"
# A milder deuteranomaly, and the same colours in greyscale
simulate_colorblind(c("#d73027", "#4575b4"), "deutan", severity = 0.5)
#> [1] "#B76123" "#4872B3"
simulate_colorblind(c("#d73027", "#4575b4"), "grey")
#> [1] "#727272" "#737373"