For the past year or so, I’ve been working on techniques for generating visually pleasing colorblind-friendly color cycles, since I find the current Matplotlib default difficult to interpret (and it ends up in many of the papers I read). While I find the default for Plots.jl slightly better, for example, I’m posting this here since I think it’s also relevant to plotting in Julia. The colorblind-friendly aspect can be solved through technical means, by enforcing minimum perceptual distances in combination with color vision deficiency simulations, but the aesthetic preference aspect is subjective and requires a different approach. To this end, I’ve created a survey for collecting the data necessary for creating a model of general aesthetic preference for color cycles:
As the usefulness of this approach hinges on collecting enough data (an amount that is difficult to define a priori), I’d appreciate folks taking the survey. Feedback on the survey or the general approach taken would also be appreciated (there’s an issue tracker). Thanks.
Nice idea! Just to let you know that there are several inbuilt color cycles for Plots, defined in PlotThemes. The color cycle used by most members of the JuliaPlots organization, and the default color cycle for Makie (on the master branch) is the wong color cycle from this paper: Points of view: Color blindness | Nature Methods, engineered to be color-blind friendly.
I’ll admit that while I looked at what colors were being used in Julia last year, I haven’t followed the more recent developments. At the time, the accessibility issue had been raised but not acted on. While the wong color cycle is accessible, it could definitely be improved upon aesthetically, since that would make people more likely to use it. It’s certainly a step in the right direction, though. Unfortunately, the Nature Methods column doesn’t seem to mention the methods used to create the color cycle.
I admit I’m slightly puzzled by this response. I congratulated you on the idea, then went to participate in your survey.
It seems strange to me that you say the color blindness issue was not acted on, given that there’s a long positive discussion on the issue you link, and the suggested color scale there was, almost immediately, added to the small list of inbuilt color cycles in Plots. Would “acted on” in your book only qualify as immediately changing the global defaults for all users (like we have even done for Makie after you “stopped following development”)? In that case you may be in for some disappointments.
Just for the record, I will just repeat my sentiment from above, that I am all for the effort of defining and aesthetically pleasing color-blind friendly color cycle, and I think your approach to defining “aesthetic” it is both interesting and promising.
@grero with respect to PerceptualColorMaps, that is indeed a nice and powerful package. It solves a slightly different problem, in that it is for generating quantitative color scales, not qualitative color cycles. Peter Kovesi has gracefully made the scales themselves available as a builtin in PlotUtils, so if you just need the gradients they are avalable as part of the default color library in Plots.
Incidentally, is there a colormap for the typical burnout of some LCD projectors, where everything becomes sort of yellowish? AFAIK it is the blue channel burning out. It is unfortunately all too common and can easily make a graph unreadable.
I probably should have been a bit clearer in that response. At the time I originally looked at it, mid October 2017, it had been discussed, but no changes had yet been made (which is in no means surprising given that the issue was only a week old). This has changed since then, e.g. the wong cycle being added in December 2017. I’m sorry for creating the wrong impression and had no intention of disparaging the work that has been done; the only point that I was trying to make was that the defaults were less than ideal when I first started looking at this.
If you do come up with a distinctive, useful, aesthetic and color-blind friendly color cycle not too far in the future you could try to talk with Simon Danisch - I don’t think the Makie defaults are in any way settled yet, though of course they will be at some time.
In the beginning it says it goes on indefinitely