Hi Federico For a possible alternative, the scico package provides a nice collection of color palettes that are designed to be both color-blind friendly and differentiable:
https://www.data-imaginist.com/2018/scico-and-the-colour-conundrum/ You could generate a vector of 21 colors (spaced as far apart as possible on the palette) to pass to your plot arguments with something like: library(scico) scico(21, palette = 'oleron') Not sure if this works for your case though. But maybe another feature (shape?) could help differentiate the 21 points. Hope this helps, Zach Simpson > Message: 11 > Date: Tue, 11 Sep 2018 07:34:51 +0000 > From: Federico Calboli <federico.calb...@kuleuven.be> > To: "r-help@r-project.org" <r-help@r-project.org> > Subject: [R] getting 21 very different colours > Message-ID: <08a6397b-4d67-4195-a53a-1fd394f72...@kuleuven.be> > Content-Type: text/plain; charset="utf-8" > > Hi All, > > I am plotting a scatterplot of 21 populations, and I am using > rainbow(21)[pops.col] to generate 21 colours for the plot (which works). > Maybe it is because I can really process few colours at a time, but the > differences between the colours are not as strong as I’d like. I can specify > start and end for rainbow(), but if anything that looks worse if I do not > just stick to 0 and 1. > > Is there a way of getting a set of 21 colours that maximises the differences > between them? > > I could pick them by hand, but that is about 15 colours more than I know (I > have a detailed colourchart, but the visual differences between ’skyblue’ and > ’slategrey’ elude me when plotted as dots on a plot). > > Cheers > > F > -- > Federico Calboli > LBEG - Laboratory of Biodiversity and Evolutionary Genomics > Charles Deberiotstraat 32 box 2439 > 3000 Leuven > +32 16 32 87 67 ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
