Home how to change default color for the value not defined when we use scale_fill_manual

Questions

how to change default color for the value not defined when we use scale_fill_manual

May 10, 2023

I have a plot like below. As I am only focusing on name %in% c("A", "B", "C") , I will not define the color for other names. By default, they were filled with dark grey. By not defining the color for those, I was able to plot D, E out without showing them in the legend.

Is it a way I can change this default color to light grey? If so , how?

# Load ggplot2
library(ggplot2)

# Create data
data <- data.frame(
  name=c("A","B","C","D","E") ,  
  value=c(3,12,5,18,45)
  )

# Barplot
ggplot(data, aes(x=name, y=value, fill=name)) + 
  geom_bar(stat = "identity")   +
  scale_fill_manual(
    values = c("A"="red", "B"="green", "C"="blue") )

>Solution :

You could use the argument na.value to change the default color to light grey like this:

# Load ggplot2
library(ggplot2)

# Create data
data <- data.frame(
  name=c("A","B","C","D","E") ,  
  value=c(3,12,5,18,45)
)

# Barplot
ggplot(data, aes(x=name, y=value, fill=name)) + 
  geom_bar(stat = "identity")   +
  scale_fill_manual(
    values = c("A"="red", "B"="green", "C"="blue"), 
    na.value = "lightgrey")