This is super neat, but the top 5 icons is a very small sample to draw any conclusions from.
If you wrote a script to fetch the icons and do the subsequent analysis, it should be trivial to modify it to fetch a few hundred icons in each category instead, which should yield more accurate results. You may find out, for example, that a few colors are just as equally represented and that there is no real "dominant" color for a category.
But if you fetched the icons by hand, this would be problematic...
And when you're showing the 5 dominant colors from the top 5 apps, you're just going to end up with the dominant color from each app. The best example of this is in Education, where the lime green of DuoLingo appears as one of the top 5 colors despite it being the only app with that color. If anything, if I were just looking at Luminosity, DuoLingo and Quizlet together I'd conclude that there isn't a dominant color for Education apps.
Yeah, the article quite a clear example of a blind application of statistical tools, the only useful thing being their idea to do quantitative design research.
The top five is only a reasonable selection if the search is for patterns linking the top contenders per category. Trying to find indication of what positively influences a top ranking in a certain category without considering what those outside the top have done is astonishingly wrong.
If you wrote a script to fetch the icons and do the subsequent analysis, it should be trivial to modify it to fetch a few hundred icons in each category instead, which should yield more accurate results. You may find out, for example, that a few colors are just as equally represented and that there is no real "dominant" color for a category.
But if you fetched the icons by hand, this would be problematic...