To cite colorspace in publications use

Ross Ihaka, Paul Murrell, Kurt Hornik, Jason C. Fisher, Achim Zeileis (2016). colorspace: Color Space Manipulation. R package version 1.3-1. URL https://CRAN.R-project.org/package=colorspace

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

Achim Zeileis, Kurt Hornik, Paul Murrell (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:

Reto Stauffer, Georg J. Mayr, Markus Dabernig, Achim Zeileis (2015). 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:

  @Manual{,
    title = {{colorspace}: Color Space Manipulation},
    author = {Ross Ihaka and Paul Murrell and Kurt Hornik and Jason C.
      Fisher and Achim Zeileis},
    year = {2016},
    note = {R package version 1.3-1},
    url = {https://CRAN.R-project.org/package=colorspace},
  }
  @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},
  }