Install using your favorite plugin manager.

To install using Vundle, add the following to your vimrc:

Plugin 'google/vim-colorscheme-primary'

To set Primary as your default color scheme, add these lines to your .vimrc:

syntax enable
set t_Co=256
set background=light
colorscheme primary

For dark mode, use set background=dark instead:

syntax enable
set t_Co=256
set background=dark
colorscheme primary

See doc/colorscheme-primary.txt for detailed instructions and additional options.

Disclaimer: This is not an official Google product (experimental or otherwise), it is just code that happens to be owned by Google.