Qualpal: Qualitative Color Palettes for Everyone

qualpal

color science

data visualization

optimization

color vision deficiency

Authors

Johan Larsson

Published

17 October 2025

Details

Journal of Open Source Software, vol. 10, pp. 8847

Links

DOI URL PDF Code CRAN

Abstract

Qualpal is a C++ library, command-line tool, R package, and web app for creating qualitative color palettes with maximally distinct colors. It helps scientists and anyone working with data visualization choose colors that remain clear and accessible. Qualpal features flexible palette generation from multiple input formats, such as the HSL and LCHab color spaces or fixed sets of RGB colors, and can adapt palettes to color vision deficiencies (CVD) across the full dichromacy spectrum at any severity. At its core, Qualpal is a lightweight C++ library with no external dependencies, making it easy to integrate into other software and programming languages.

Citation

BibTeX citation:

@article{larsson2025,
  author = {Larsson, Johan},
  title = {Qualpal: {Qualitative} {Color} {Palettes} for {Everyone}},
  journal = {Journal of Open Source Software},
  volume = {10},
  number = {114},
  pages = {8847},
  date = {2025-10-17},
  url = {https://joss.theoj.org/papers/10.21105/joss.08936},
  doi = {10.21105/joss.08936},
  issn = {2475-9066},
  langid = {en},
  abstract = {Qualpal is a C++ library, command-line tool, R package,
    and web app for creating qualitative color palettes with maximally
    distinct colors. It helps scientists and anyone working with data
    visualization choose colors that remain clear and accessible.
    Qualpal features flexible palette generation from multiple input
    formats, such as the HSL and LCHab color spaces or fixed sets of RGB
    colors, and can adapt palettes to color vision deficiencies (CVD)
    across the full dichromacy spectrum at any severity. At its core,
    Qualpal is a lightweight C++ library with no external dependencies,
    making it easy to integrate into other software and programming
    languages.}
}

For attribution, please cite this work as:

Larsson, Johan. 2025. “Qualpal: Qualitative Color Palettes for Everyone.” Journal of Open Source Software 10 (114): 8847. https://doi.org/10.21105/joss.08936.