Faceted histogram with alternating colors (for clarity)

[jefriedel]

I am trying to create a set of histograms where the column colors within the histogram alternate. I have the histogram displaying 50 bins for users to be able to do some simple diagnostics of their results. I am just trying to increase the contrast between the adjacent columns. Additionally, the data could have groupings so sometimes we need facet_wrap sometimes we don't.

I can get the column colors to alternate colors by manually setting the fill. But, when I facet_wrap the plot object the colors don't expand out to the facets and I get Error: Aesthetics must be either length 1 or the same as the data (X): fill). Is there a way to expand the alternating colors to the faceted plots?

Simplified reprex that has groups and faceted data:

library(tidyverse)

data = tibble(
  data = rep(1:4,3),
  groups = c(rep("A",4),rep("B",4),rep("C",4))
)

p = ggplot(data) + 
      geom_histogram(aes(x = data),
                 bins = 4,
                 color = "black",
                 fill = rep(c("#e69f00","#009ee9"),2))

#Histogram of everything
p

p =  p + facet_wrap(vars(groups))

#Faceted histogram
p

[nirgrahamuk]

library(tidyverse)

(data = tibble(
  data = rep(1:4,3),
  groups = c(rep("A",4),rep("B",4),rep("C",4)),
  myfill = rep(c("#e69f00","#009ee9"),6)
))

p = ggplot(data) + 
  geom_histogram(aes(x = data, fill = I(myfill)),
                 bins = 4,
                 color = "black"
                )

#Histogram of everything
p

p =  p + facet_wrap(vars(groups))

[jefriedel]

That seems to solve some of my problems. Thanks!