Introduction to Color Palettes in R with RColorBrewer

RColorBrewer is an R Programming Language package library that offers a variety of color palettes to use while making different types of plots. Colors impact the way we visualize data. If we have to make a data standout or we want a color-blind person to visualize the data as well as a normal person we have to use the right color palette. RColorBrewer does exactly that by compiling the right colors in palettes for a variety of use cases.

Installation

To install the RColorBrewer package in R Language we can use a cran mirror using:

R

# install RColorBrewer
install.packages("RColorBrewer")

After running this, select the desired cran mirror from the list of available mirrors and the package will be installed.

Now for using RColorBrewer, we can use

library("RColorBrewer")

RColorBrewer provides the following three types of palettes suitable for most common use cases:

1. Sequential color palettes:

The Sequential color palettes have colors ordered in intensity and saturation. So, they are best for the visualization of data that is ordered and progresses from high to low. We can see all sequential color palettes using:

R

display.brewer.all(type="seq")

Output:

Sequential color Palettes

2. Diverging color palettes:

The Diverging color palettes have colors ordered from hot to neutral to cool. So, they are best for the visualization of data that has an emphasis on middle values and both sides of the end values. We can see all diverging color palettes using:

R

display.brewer.all(type="div")

Output:

Diverging Color Palette

3. Qualitative color palettes:

The Qualitative color palettes have colors that are visually contrasting and different. So, they help create the primary visual differences between different categories or groups of data. We can see all Qualitative color palettes using:

R

display.brewer.all(type="qual")

Output:

Qualitative color palettes

We can list all the colors with their key information using:

R

brewer.pal.info

Output:

         maxcolors category colorblind
BrBG            11      div       TRUE
PiYG            11      div       TRUE
PRGn            11      div       TRUE
PuOr            11      div       TRUE
RdBu            11      div       TRUE
RdGy            11      div      FALSE
RdYlBu          11      div       TRUE
RdYlGn          11      div      FALSE
Spectral        11      div      FALSE
Accent           8     qual      FALSE
Dark2            8     qual       TRUE
Paired          12     qual       TRUE
Pastel1          9     qual      FALSE
Pastel2          8     qual      FALSE
Set1             9     qual      FALSE
Set2             8     qual       TRUE
Set3            12     qual      FALSE
Blues            9      seq       TRUE
BuGn             9      seq       TRUE
BuPu             9      seq       TRUE
GnBu             9      seq       TRUE
Greens           9      seq       TRUE
Greys            9      seq       TRUE
Oranges          9      seq       TRUE
OrRd             9      seq       TRUE
PuBu             9      seq       TRUE
PuBuGn           9      seq       TRUE
PuRd             9      seq       TRUE
Purples          9      seq       TRUE
RdPu             9      seq       TRUE
Reds             9      seq       TRUE
YlGn             9      seq       TRUE
YlGnBu           9      seq       TRUE
YlOrBr           9      seq       TRUE
YlOrRd           9      seq       TRUE

ColorBlindness filter

In the above information, there is also a column for colorblindness information. This column tells whether a colorblind person can see all the colors of the palette or not. So, we can use this information to get all the color palettes suitable for colorblind people. We can view all such palettes using:

R

display.brewer.all(colorblindFriendly=TRUE)

Output:

Colorblind friendly palette