Darken colors by mixing them with black.
Usage
darken(col, amount = 0.2)
Arguments
- col
vector of valid R colors.
- amount
numeric value between 0 and 1 specifying the
amount of darkening. A value of 0 leaves the color unchanged,
while 1 returns black.
Value
Character vector of hexadecimal colors.
Details
Colors are mixed linearly with black in RGB space:
$$
x_{new} = x \cdot (1 - amount)
$$
Examples
darken("tomato")
#> [1] "#CC4F38"
darken(c("tomato", "royalblue"), amount = 0.5)
#> [1] "#7F3123" "#203470"
# increasing amounts
amount <- seq(0, 1, 0.2)
barplot(rep(1, 6), col = sapply(amount, darken, col = "tomato"),
names.arg = amount, yaxt = "n", xlab = "amount")
