qualpalr 0.3.0

New features

• Improved algorithm for finding distinct colors. (For details
  see this.)
• Revamped the color deficiency handling to include almost all cases of color
  deficiency using the methods described in
  Machado 2010,
  now including tritanopia as well as anomalous trichromacies (deuteranomaly,
  tritanomaly, and protanomaly). This is controlled via the cvd_severity
  argument to qualpal() that allows the user to set the severity of color
  deficiency to adapt to: 0 for normal vision and 1 for dichromatic vision
  (protanopia, deuteranopia, or tritanopia).

Minor improvements

• Distance and color picking algorithms have been rewritten in C++ using Rcpp,
  RcppParallel, and RcppArmadillo.
• Phased out the ... argument to qualpal.
• Lightness range of the predefined rainbow palette increased to [0, 1].
• Changed argument name of colorblind to cvd (for color vision deficiency)
  since the function now adapts to less severe versions of color deficiency. Using
  colorblind is deprecated and will throw a warning.

Bug fixes

• Fixed typos and invalid links in the Introduction to qualpalr vignette.