Aubrey Nelson
The light can come from the Sun, fire or a lamp sending waves of different lengths. The combination of waves that hit the cones form in our brain the perception of color.
The second type is sensitive to middle wavelengths (starting at orange, peaking at green, and declining at blue). The third type is sensitive to short wavelengths (starting at green and peaking at blue). There are three common types: protanopia (red-blind), deuteranopia (green-blind), and tritanopia (blue-blind). About 8% of men and 0.5% of women are colorblind, so making your chart color blind safe is a reasonable thing to do.
Most of the issues for colorblind people come from the prevalence of red-and-green combinations as a pair of opposites in design. The first rule of making a palette for colorblind – avoid combining red and green. So if you’re aiming to create a color blind-friendly palette try to use only two basic hues: blue and red (orange and yellow will also fit).
All the variations can be made by using different saturation or lightness of the basic color. As you can see the palette worked for all types of color blindness, but you should always be aware that the variation of color-blind colors can vary significantly from person to person, so it’s always important to double-check. But remember, if the palette is grayscale one should use other tools to distinguish chart elements.
You can access it under View > Proof Setup > Color-Blindness - Protanopia-type or Deuteranopia-type. Typically, it’s better to use direct labels instead of a legend – it saves the time and attention of a reader. Another advantage of direct labels is its ability to fix the usage of palettes that are not color blind friendly.
Our recommendations are based on how easily one or the other chart can work without any color coding. Check this resource page and learn how to design the best dot plots that will impress your audience. X- and Y- axes, size, and different icons provide 4 dimensions already which is easily enough for most of the visualization tasks.
Heatmaps are heavily dependent on color, so the only way to make it safe for colorblind readers is to use one hue or grayscale palette. Icon array is a rare case of a part-to-whole chart that doesn’t depend on colored areas or sectors.
Surely, a treemap can be made also with a mono hue palette or just with the help of stroke borders, but the lack of color will weaken its visual strength, especially if a complex hierarchical structure should be presented. The simplest and most flexible temporal chart that can be modified in various ways to make it readable for a colorblind audience.
In the case of multiple categories, the line width can be modified as well as various types of dashed strokes. Discover even more pro design tips on our dedicated line chart resource page and advance your data visualization with Datylon.
A one-dimensional heatmap can quickly become a bad choice if multiple colors are used. ➡️ If you want to apply all these tips and make your data visualizations truly inclusive for different types of audiences, you need the full freedom of design to do so.
