To cite colorspace in publications use:

Zeileis A, Fisher JC, Hornik K, Ihaka R, McWhite CD, Murrell P, Stauffer R, Wilke CO (2020). “colorspace: A Toolbox for Manipulating and Assessing Colors and Palettes.” Journal of Statistical Software, 96(1), 1–49. doi: 10.18637/jss.v096.i01.

If you use HCL-based color palettes, please cite:

Zeileis A, Hornik K, Murrell P (2009). “Escaping RGBland: Selecting Colors for Statistical Graphics.” Computational Statistics \& Data Analysis, 53(9), 3259–3270. doi: 10.1016/j.csda.2008.11.033.

If you use HCL-based color palettes in meteorological visualizations, please cite:

Stauffer R, Mayr GJ, Dabernig M, Zeileis A (2009). “Somewhere over the Rainbow: How to Make Effective Use of Colors in Meteorological Visualizations.” Bulletin of the American Meteorological Society, 96(2), 203–216. doi: 10.1175/BAMS-D-13-00155.1.

Corresponding BibTeX entries:

  @Article{,
    title = {{colorspace}: A Toolbox for Manipulating and Assessing
      Colors and Palettes},
    author = {Achim Zeileis and Jason C. Fisher and Kurt Hornik and
      Ross Ihaka and Claire D. McWhite and Paul Murrell and Reto
      Stauffer and Claus O. Wilke},
    journal = {Journal of Statistical Software},
    year = {2020},
    volume = {96},
    number = {1},
    pages = {1--49},
    doi = {10.18637/jss.v096.i01},
  }

  @Article{,
    title = {Escaping {RGB}land: Selecting Colors for Statistical
      Graphics},
    author = {Achim Zeileis and Kurt Hornik and Paul Murrell},
    journal = {Computational Statistics \& Data Analysis},
    year = {2009},
    volume = {53},
    number = {9},
    pages = {3259--3270},
    doi = {10.1016/j.csda.2008.11.033},
  }

  @Article{,
    title = {Somewhere over the Rainbow: How to Make Effective Use of
      Colors in Meteorological Visualizations},
    author = {Reto Stauffer and Georg J. Mayr and Markus Dabernig and
      Achim Zeileis},
    journal = {Bulletin of the American Meteorological Society},
    year = {2009},
    volume = {96},
    number = {2},
    pages = {203--216},
    doi = {10.1175/BAMS-D-13-00155.1},
  }