https://samanthaz.me/writing/finding-the-right-color-palettes-for-data-visualizations
While good color palettes are easy to come by these days, finding the right color palette for data visualizations is still quite challenging.
At Graphiq, things are arguably made even more difficult, as we need to convey information across thousands of unique data sets in many different types of visualization layouts.
Rather than diving in head first and creating our own color palette, we started by conducting some research on existing color palettes around the web. Surprisingly, we found that few are actually designed for complex charts and data visualizations. We identified several reasons as to why we couldn’t use existing color palettes:
Problem 1: Low Accessibility
Many of the color palettes we looked at were not designed for visualizations. Not only do they not vary enough in brightness, but they were often not created with accessibility in mind. Flat UI Colors is one of the most widely used color palettes out there, and it’s easy to see why: it looks great. But, as its name indicates, it’s designed for user interfaces. Those who are color blind may find it difficult to interpret a data visualization that uses the Flat UI palette:
Flat UI Colors in full colors, protanopia mode, and grayscale.
Problem 2: Not Enough Colors
Another problem is that many existing color palates did not have enough colors. When building Graphiq visualizations, we need a palette that offers at least six colors, if not eight to twelve colors, to cover all of our use cases. Most color palettes we looked at did not provide enough options.
Here are a few examples from Color Hunt:
While they are good color palettes, they are not flexible enough to present complex data series.
Problem 3: Hard to Distinguish
But wait a second, there are color palettes that are like gradients — theoretically one can create any number of colors from that, right?
Unfortunately, there’s often not enough variation in brightness, and many of them would become indistinguishable very quickly, like these ones, also from Color Hunt:
