A color palette for 20 elements.
This is one palette option for users who have <= 20 elements to plot. The palletes of RColorBrewer package provide at most 12 discrete colors, such as "Set3" and "Paired". This palette is adapted from D3.js library and can be used as a supplement.
color_palette_20
An object of class character of length 20.
Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.