How to change background colour of legend in ggplot2?
You can use the legend.key parameter of theme. From ?theme:
legend.key: background underneath legend keys (element_rect(); inherits fromrect)
That is
theme(legend.key = element_rect(fill = "black"))
An example:
a <- seq(1:5)b <- seq(1:5)c <- seq(1:5)d <- data.frame(a, b, c)ggplot(data = d, aes(x = a, y = b, color = factor(c))) + geom_point() + theme(legend.key = element_rect(fill = "yellow"))produces:
