I am red-green colorblind. So certain shades of colors like that I literally can't see. Blue and purple are issues, and certain shades of yellow and green.

In the image above, I cannot really see a difference in the extremes of the legend. The gradient is definitely not helping. I can see the difference when put near each other. Like Mississippi and New Mexico are clearly on opposite sides, but I would not be able to tell you which direction either leaned because I can't see what the legend is showing. Likewise most of the states mean nothing to me since they're part of the gradient itself going towards colors I can't distinguish a direction from. Without the numbers, this map would mean nothing to me.

Simply put, pick colors on opposite sides of the color wheel when trying to show differences like this with gradients and you're more likely to to okay. Don't pick colors that are next to each other. TRhis might as well have been a blue/purple gradient with an extra z-dimension for time or some crap,

It's not gray, almost no one actually sees in greyscale, despite the jokes. It's always just certain shades the eyes can't distinguish differences from.

A good example for other common colors, is peanut butter looks like a shade of like greenish tan or maybe dark khaki, not brown as most people describe it to me.

A decent resource to explain visually for those that can actually see the full range of color: https://enchroma.com/blogs/beyond-color/how-color-blind-see

[–] Flughoernchen@feddit.de 6 points 1 year ago* (last edited 1 year ago) (1 children)

Hey there, sorry to bother you even more, but I've got a follow up question. You said working with complementary colors ("opposite sides of the color wheel") might work better, so in general it's easier to distinguish for red-green colorblind people. I've always thought it was especially hard to distinguish red from green in those cases, but red and green are complementary colors. Where did I go wrong here? Is it something I misunderstood from your explanation or is it my understanding of red-green colorblindness that's just wrong?

[–] Norgrimm@feddit.de 5 points 1 year ago

They are complementary, but not on the opposite side of the color wheel. They are primary or secondary complements, depending on if you are in additive (light) or subtractive (paint) color-space. The exact opposite of red is cyan, and the opposite of green is magenta

[–] Viking_Hippie@lemmy.world 5 points 1 year ago

most of the states mean nothing to me

Not colorblind, but same 🤷

[–] choss@lemmy.ml 2 points 1 year ago

Thanks for the writeup! If I were giving a presentation explaining the Four Color Theorem, which four colors should I choose to accomodate folks with colorblindness?