Dealing with colors in base R

Color is one of the most important component of a data visualization.

R offers some awesome functions to deal with it. This post should guide you through

the basics, from calling a single color to building a neat color palette.

Note however that dealing with color is much simpler using ggplot2, and that the gallery

offers a dedicated section to color management with ggplot2.

Picking one color with R

There are 5 main methods to call a color in R. Click the buttons below to see a description of them

Name rgb() Number Hex code

Name → The most common method is to call a color by its name. R offers about 657 color names. You can read all of them using colors().

rgb() → The rgb() function allows to build a color using a quantity of red, green and blue. An additionnal parameter is available to set the transparency. All parameters ranged from 0 to 1.

Number → Also possible to call a function by its number. For instance, if you need the color number 143, use `colors()[143]`.

Hex code → All colors can be defined by their hex code. A hex code looks like this: #69b3a2. To find the hex code of your dream, visit this color picker.

Pick a color

Build a color palette with RColorBrewer

RColorBrewer is the most famous package when it comes to build color palette with R. It provides quality continuous, sequential and categorical color palette. Examples below should get you started with this package, and give you an overview of all the available color palettes.

Basic usage

Basic usage to build a 5 color long palette.

Longer palette

Get a longer color palette from RColorBrewer.

Available palette

See the complete list of available palettes.

Other palette: use paletteer

The paletteer package gives access to all the existing color palettes in R.

A list of all the available palettes in R
To get the hex code of a palette: library(paletteer) ; paletteer_c("viridis::inferno", n=10)

Set color according to a variable in base R

Once you've found a color palette you like, you probably need to map it to a categorical or a numeric variable. This pretty easy to do with ggplot2, but much harder in base R. Basically, you have to transform the variable of interest in an integer that will be used to call the appropriate color.

Categorical palette

How to map a color to a categorical variable.