Flag Day 2023:

DataVizzers Love Flags!

Julie Peasley
5 min readJun 14, 2023

In honor of Flag Day, a holiday most people probably overlook, I would like to showcase a special group of data visualizations: examining the attributes of the flags of the world. In many ways, the collection of flags is the perfect subject for insightful infographics and colorful charts. It’s a solid dataset, with many color and shape variables ranging across a consistent, uniform area (rectangle… except you, Nepal, with your double triangles). I kept discovering different visualizations of world flags that it has come time to make a listicle. Studying these pieces is not only a wonderful experience of exploration, but you will come out knowing your world flags better than ever.

1. Shahee Ilyas wins for being the earliest flag data analysis that I could find published online. In a 2007 project using a Python script, he calculated the relative proportions of each flag’s colors and divided them into pie charts. A simple idea, but impressive. The flags become generative art, a multicolor array of gorgeous circles, many similar, but no two the same.

Shahee Ilyas

As an extra, he mixed each flag’s colors to create a final solid color for each flag. The result is interesting because a country’s color might not be what you would expect. Sweden, with its yellow and blue flag, becomes a muted forest green. The United States is a dusty mauve, for example. I can envision this becoming some sort of cryptic cypher for countries to which this is the color key. I would like to see this spectrum arranged by color, as a worldwide gradient scale.

Bonus: Shahee has a cool web widget called PhotoPie that allows you to convert any image into a pie chart of its relative color constituents. I had fun with this!

2. Martin Krzywinski
In 2017, data visualizer extraordinaire Martin Krzywinski takes the same idea of reimagining each flag according to its color proportions circularly, but he chooses to show it via concentric circles, in something closer to a donut chart. Again, the grid of world flags becomes a beautiful poster of generative art (available for purchase). Martin digs deep into the technical specifications and addresses visual problems such as colors that read perceptually different from their actual mathematical proportions and shows how he fixed this with “perceptual radius scaling.” The flags of Ukraine and Sweden, for example, are almost identical in their proportions of yellow and blue. Using advanced math equations that were over my head but I can appreciate, he devises a system that mixes just the right quantities of colors to compensate how the human eye perceives them. The result is stunning. The story of his process is beautifully detailed here.

Martin Krzywinski

3. Nicholas Rougeux
One of my favorite data storytellers and designers is Nicholas Rougeux. On his site c82.net you will find a gorgeous collection of data visualizations on esoteric topics ranging from prime numbers to British minerology, from Byrne’s Euclid to an 1892 treatise on color. In 2015, Nicholas set out to sort the world flags by color combination, as documented here. He goes through several iterations before getting it just right and his final result is a mesmerizing, unique piece of art that uses elements of circle packing, alluvial streams and colorful nodes, all arranged in a blossoming, flowery array. We can easily see that generally speaking, the flags fall into distinct color groups from a combination of 7 basics: red, orange, yellow, green, blue, black and white. This piece is also available for purchase.

Nicholas Rougeux

4. Giulia De Amicis
In her 2022 post on Visual Capitalist, data visualizer Giulia De Amicis sorts the world flags into groups not by color, but pattern. In one delightfully satisfying infographic, she arranges the 196 flags into 12 visual element categories: canton, geometry, stripes, stars, cross, diagonal, crescent, bicolor, tricolor, seal, circles and miscellaneous. What do Canada and Kiribati have in common? Their flags contain uncommon elements that no other flags share. We also learn that red is the most common color, comprising 20% of flags.

Giulia De Amicis

5. Reddit user Udzu. In their 2018 r/dataisbeautiful (Reddit) post, “Udzu” tries something completely different. By numerically averaging the colors, they create deconstructed versions of flags by global region, abstractions which could be at home in any gallery of post-modern art. We see that red dominates the flags of Asia, Europe and North and Central America (which tends to also prefer an equal amount of blue) but green dominates for South American in certain treatments. This was also posted by Visual Capitalist in 2018.

Udzu (r/dataisbeautiful)

6. Flag Stories. This final one is by far the most comprehensive set of visualizations and staggering in the amount of work that was put into it. Flag Stories, “a project by Ferdio” is an entire website charting every possible statistical aspect of world flags. Ferdio treats us to eye-catching visualizations such as bar charts, a delightful “flag tetris”, the history of each flag’s design iterations over time (America has the most at 32) and layouts of individual elements from each flag’s design. For example, countries with similar flags are compared (don’t confuse Ireland with Cote D’Ivoire). Ferdio even breaks down each flag’s proportions and charts them visually by aspect ratio. You also get a detailed world flag timeline (Denmark is oldest). For each continent, Ferdio generates an invented flag using the most common colors, symbols and layouts. These seem intuitively spot on, though they are generatively created from the data. There is a flag lookup matrix chart that shows us how the elements and colors are combined. Did you know there are regional flag “families”? (Scandinavian countries prefers crosses).

Today (June 14) is Flag Day in the U.S., but did you know several other countries have their own—different—Flag Days? I learned so much about the world just by studying these beautifully designed visualizations. With a total of 23 separate visualizations, “Flag Stores” is just incredible!

One of the 23 different Flag Stories / A project by Ferdio

In conclusion, you will never look at world flags the same way again after studying these informative and delightful charts. They are charts as art. And if you happen to find more flag visualizations, please send them my way!

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Julie Peasley

Graphic Designer specializing in data visualization / infographics / journalistic storytelling.