ggplot boxplot multiple groups of y with continuous x

Question

I want to produce a boxplot for multiple groups y with continuous x. I give an example as follows:

library(ggplot2)
ggplot(diamonds, aes(carat, price)) +
  geom_boxplot(aes(group = cut_width(carat, 0.25), colour=color))

I get the figure as follow:

However, the 'colour' does not work here. Could anybody help me to fix this problem? Thanks in advance.

Answer 1

You need to also group by color (otherwise it will group different colors together):

ggplot(diamonds, aes(carat, price)) +
    geom_boxplot(aes(group = interaction(cut_width(carat, 0.25), color), colour=color))