[Isochrones] Use a color scale that is colorblind friendly

[wcedmisten]

Description

What kind of feature you are suggesting?

Currently the isochrones demo uses a red-green color scale for the contours.

Unfortunately these colors are not very accessible for people who are colorblind, which affects around 8% of the male population.

Since the colors convey meaning (green = near, red = far), it would be great to use a color scheme that is more accessible for colorblind people.

Does it solve any problem?

Better understanding of the isochrones for colorblind people.

Proposed Solution

Personally I've used the Viridis color scale in my own projects for isochrones, but there are other color scales that are colorblind friendly.

Screenshots

Additional information

https://blog.bioturing.com/2018/09/24/heatmap-color-scale/

[chrstnbwnkl]

Sounds like a meaningful enhancement to me. In your own project, you're using a grayscale base map though, whereas we're using the far more colorful standard Mapnik style. Would you mind giving it a shot to see how this would look like in combination?

[jakern]

I made an attempt at this because the opacity of many isochrones was bothering me. Branch is here

Example of original where many isochrones overlapping would make map unreadable.

New Gradiant example

Wider angle to try to see if the is enough color variability to differentiate the colors.

Example with fewer contours that highlights the problem of differentiation.

[jakern]

the single isochrone being yellow is pretty terrible though. I'll need to re-work but any feedback on the current version would be helpful.

[nilsnolde]

IMHO there'll always be examples where it's very very hard to tell them apart. E.g. if you do it without any generalization or denoising, the color palette won't matter much. FWIW, I like your style a lot better than what we have currently! Thinking out loud: would it be messy to make a finite set (3-4) of color palettes user selectable, possibly also opacity?