Colorblind-safe categorical map? about colorcet

[jbednar]

The way the categorical colors are generated is to create a gamut of possible colors, then iteratively choose colors within that gamut that are most dissimilar from all the preceding colors. You could use a color-blind-safe definition of color similarity when doing so, but that would require modifying the underlying code. I think it's probably easier to simply prune out non red-green colorblind-safe colors by eliminating either the green or the red portion of the gamut. In fact, the cool and warm Glasbey variants already do this:

These color sets were not intentionally constructed to be colorblind safe, and you can probably do a better job if you have a good model to guide which colors to select, pruning specifically the ones likely to be confused by a dichromat. We'd be happy to accept a contribution of improved cool or warm color sets that are specifically validated for their colorblind safety properties, using either method (dichromat-safe color similarity metric, or color space pruning).

In any case, note that the specific set you mention (glasbey_category10) is constructed by taking the first 10 colors as fixed (from the externally defined D3 category10 colormap). Those 10 colors include red and green, so any color set starting with those colors will never be colorblind safe. So it is not possible to create anything like glasbey_category10, intended as a drop-in replacement for and extension of category10; it would need to be something like our cool or warm palettes that avoid the confusing red/green combination.

[jbednar]

Closing since there's a solution for now, but we'd still be happy to accept a specifically constructed colorblind-safe categorical map.