Thankfully, science has once again come to the rescue. Researchers, including Nuñez, at the US Department of Energy have created a color scale using state-of-the-art mathematical modeling and optimization techniques that aims to solve our rainbow-related misery. Dubbed "cividis" – the rainbow scheme we're used to, by the way, is called "jet" – the scale runs from dark blue to light yellow, is usable by colorblind people, and, crucially, is "perceptually linear" – so the perceived changes in color really do match actual changes in data. Their results are published in the journal PLOS ONE.
So why, despite all its issues, do we keep coming back to the rainbow? The problem, cartographer and rainbow-critic Kenneth Field told Scientific American, is simply that "[p]eople love colorful maps." This is something Nuñez's team is all too aware of – a drawback of their color system, the study notes, is that "its minimal coverage of different colors... keeps cividis from being as aesthetically pleasing as [other maps]."
Unfortunately, it seems that as pretty as rainbows are, they're basically useless – or downright dangerous – as data tools. When it comes to scientific analysis, explained Field, "[r]ainbows cause more problems than they solve."
[H/T: Scientific American]