Tol High Contrast
Paul Tol — highcontrast scheme
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#004488 -
#ddaa33 -
#bb5566
A synthetic demo grid, classed with equal intervals — the point is the palette against real basemap ink, not the data. Switch themes to see how much basemap the palette leaves room for.
Metadata
Provenance
High contrast is Tol's three-color scheme — deep blue, gold, dusty red — designed to be distinguishable not only under color vision deficiency but also when converted to grayscale, because the three differ in lightness as well as hue. It is the scheme he recommends when a figure must survive photocopying or a monochrome journal. Transcribed from khroma's copy of his published lists.
When to use it
The safest possible choice for a two- or three-category map: before and after, control and treatment, yes and no and unknown. Because the three colors differ in lightness, the map still works if a reader prints it in black and white, which is the failure mode most palettes ignore. Do not stretch it past three classes by interpolating — the grayscale separation is exactly what you would lose.
License
Free to use with citation (no formal license) · source
The color specification carries this license, which is separate from the MIT license on this site. See attribution.