Colour schemes for maps and charts

A few useful resources:

• Colorbrewer: hand-picked colour schemes by Cynthia Brewer, designed for maps but also useful for other visualisations. All of the palettes are available in the RColorBrewer package for R. This is a useful introductory paper on data maps by Cyntia Brewer.
• Escaping RGBland is a paper by Zeileis, Hornik and Murrell describing principles for creating your own Colorbrewer-like schemes. Section 6 describes the colorspace package in R, which makes it easy to put the paper's principles into practice.
• The Cookbook for R includes a couple of nice simple colourblind-friendly palettes, based on this page on Color Universal Design.
• I Want Hue is a good tool for creating categorical palettes.
• Here is a much more comprehensive list of resources from Visualising Data.