On Thu, Nov 3, 2011 at 10:26 AM, Max Kuhn <mxk...@gmail.com> wrote: > First, can anyone verify that these the colors in col2 are > differentiable to someone who is color blind? > > Second, are there any other specific palettes that can be recommended? > How do the RColorBrewer palettes rate in this respect?
If you go to www.colorbrewer.org, the ColorBrewer site, it has ratings of the palettes for visibility under a variety of conditions, including red-green color blindness. Some of them are good, but not all of them. The dichromat package attempts to show the impact of both sorts of red:green anomalous vision on color visibility. It isn't quite right because of gamma correction, but people have told me that it is a fairly good representation, and it does have the right impact on clustering of pixels in some of the Ishihara color vision tests. It suggests that your colors 1 and 3 will be too similar and 2 and 4 will also be too similar for someone with protanopia. You aren't going to be able to get five colors that are equal luminance, equal chroma, and distinguishable to dichromats: you're putting three constraints on a three-dimensional space and you will end up with just two points. For three colors I would suggest orange, blue, gray. More than three will be hard. -thomas -- Thomas Lumley Professor of Biostatistics University of Auckland ______________________________________________ R-help@r-project.org mailing list 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.
