Improve consistency and accessibility of metanode colors

[vincerubinetti]

old:

new:

@dhimmel

[dhimmel]

The side-by-side comparison is nice.

A few things we might also want to include in this PR:

• git mv hetnet/neo4j/docker/guides/graphstyle.grass hetnet/neo4j/docker/guides/graphstyle-legacy.grass
• update graphstyle.grass with the new colors

Then following this PR we probably want to update the two metagraph visualizations here. I made these with the macOS OmniGraffle program. Perhaps I could dust off the old machine to update them.

[vincerubinetti]

[dhimmel]

looks good to me. @vincerubinetti let me know when you are done making changes.

[dhimmel]

Ah cool, yes must have been an oversight not to put this here.

[vincerubinetti]

Done 👍 ready to merge

[dhimmel]

We were asked by a reviewer about the whether the Hetionet color palettes are color blind friendly, so I made the following figure using http://hclwizard.org:3000/cvdemulator/:

It's interesting to see how the colors appear based on different color vision deficiencies. Many of the colors are still differentiable. Also we often show the metanode name or abbreviation along with the colors, such that I don't think any action is needed, just something to consider.

[vincerubinetti]

I don't proclaim to be an expert in accessibility or color theory, but I think the best way to make something "color blind friendly" is to make it not rely on colors at all, as you said. Then colors can just be a bonus. I think there's only so much you can do when certain color blindnesses limit you to only ~3 hues, and we have 8 types here. A true expert in color accessibility could probably tweak the brightnesses and saturations and such to be slightly more differentiable, but probably not worthwhile enough to change all the code and figures. I believe I made sure to have text or initials everywhere we used these colors on the website and in connectivity search.

[dhimmel]

I believe I made sure to have text or initials everywhere we used these colors on the website and in connectivity search.

Yes. The visualizations would work without color at all, but would be less pretty.

Looking at the commits in this PR, I see 7417ce9 with message, "improve consistency and accessibility of metanode colors", so I'm inclined to think that accessibility was a criteria for your revisions.