To cite package ‘shades’ in publications use:

  Clayden J (2019). _shades: Simple Colour Manipulation_. R package
  version 1.4.0, <https://github.com/jonclayden/shades>.

A BibTeX entry for LaTeX users is

  @Manual{,
    title = {shades: Simple Colour Manipulation},
    author = {Jon Clayden},
    year = {2019},
    note = {R package version 1.4.0},
    url = {https://github.com/jonclayden/shades},
  }

ATTENTION: This citation information has been auto-generated from the
package DESCRIPTION file and may need manual editing, see
‘help("citation")’.