Sequential grey colour scales

Based on gray.colors. This is black and white equivalent of scale_colour_gradient.

scale_colour_grey(..., start = 0.2, end = 0.8, na.value = "red")

scale_fill_grey(..., start = 0.2, end = 0.8, na.value = "red")

Arguments

...	Other arguments passed on to discrete_scale to control name, limits, breaks, labels and so forth.
start	gray value at low end of palette
end	gray value at high end of palette
na.value	Colour to use for missing values

See also

Other colour scales: scale_alpha, scale_colour_brewer, scale_colour_gradient, scale_colour_hue

Examples

p <- ggplot(mtcars, aes(mpg, wt)) + geom_point(aes(colour = factor(cyl)))
p + scale_colour_grey()
p + scale_colour_grey(end = 0)

# You may want to turn off the pale grey background with this scale
p + scale_colour_grey() + theme_bw()

# Colour of missing values is controlled with na.value:
miss <- factor(sample(c(NA, 1:5), nrow(mtcars), replace = TRUE))
ggplot(mtcars, aes(mpg, wt)) +
  geom_point(aes(colour = miss)) +
  scale_colour_grey()
ggplot(mtcars, aes(mpg, wt)) +
  geom_point(aes(colour = miss)) +
  scale_colour_grey(na.value = "green")