So the different components of this visualization genuinely solve a few different problems around color-blindness (necessary for 508 compliance is my guess, but I'm not an expert here)
Grab a screenshot (https://i.imgur.com/9ynIz5G.jpg) and drop it in here (https://www.color-blindness.com/coblis-color-blindness-simul...)
The only mode where any two zones next to each other are nearly identical is Red-blind/Protanopia (CMK identical, Y 8% higher in UTC-7 compared to UTC-8†). Monochromacy/Achromatopsia is a close second... and that's where the gradients to the clocks come in - even for those users, there's still a mechanism to distinguish those two zones.
I'd guess some serious usability research went into this.
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† RGB, though more accurate since we're talking about a screen, would've been a little more complicated to compare in writing since only yellow changed between the two in CMYK
I find that unlikely. If they just swapped the blue color of Alaska with the Mountain time zone there would be no ambiguity between adjacent colors at all for any type of color blindness.
Interesting to wonder how often are people needing to come up for a design for this type of information? Am I wrong to think not very often? My point is it's cool to see a design for something that isn't "solved" or that not many have ever really worked on.