Option to use perceptually uniform colormaps



  • It does not appear that the current colormaps used are perceptually uniform. This tends to create artificial visual artifacts when looking at the heatmaps. For example, if you look between 69F and 72F, there seems to be a big "visual" change. However between 72F and 75F, there is a much less change. A perceptually uniform heatmap would not have this issue.



  • @cookieoffortune Hello, yes this is intentional ! We wanted to emphasize specific temperature thresholds (e.g., freezing = 0 C / 32 F). More details are in this reply by @TZ



  • @dzuremar Can we have an option to pick where these subgradients occur and have the option for the subgradients to use a perceptually uniform colormap? For me at least, I can see 100F to be useful subgradient, but I would prefer something uniform in between. The reason for this is it makes it easier to determine "how much" colder or warmer a location is by just looking at the color instead of having to track down the actual numbers. This is not easily doable if the colormap is not perceptually uniform.



  • +1 for uniform colorscales! Accurately perceiving differences in the data seens quite important. The propoposal above to allow interactively modifying the nonlinearity in the colormap seems a bit overboard in my opinion, but I think a single checkbox would be great!

    I'm interested in the current colormap for wind speed. The largest nonlinearities seem to occur around 25kt, 35kt, and 45kt, but I'm not sure whether they are distinctive enough to be intentional. Are these characteristic speeds that you found useful to represent? Also, it's a bit curious that very high and very low speeds are nearly the shade of blue.

    Thanks for the great work in making high quality weather data available for everyone!
    Oliver



  • Here is a current screenshot from the Android app for reference.

    Windy Android Windspeed Colormap 2018/1/23


  • Sailor

    @oliverevans96
    On Windy.com (not in the phone App) you can modify the colormaps as you like.
    Go to Settings -> Modify layer colors
    https://community.windy.com/topic/6455/colors/2
    The modification will be applied to your phone App.

    Here is a lot of examples of modified colors
    https://community.windy.com/topic/7036/version-2-windy-customized-graphics


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