They did mention it just for anyone curious "Viz Palette also makes it easy to check if your colors can be distinguished by colorblind people. A browser extens

They did mention it just for anyone curious "Viz Palette also makes it easy to check if your colors can be distinguished by colorblind people. A browser extension like Spectrum, an online tool like Coblis or an app like Sim Daltonism can simulate the colors as seen by people with different types of colorblindness, too. In Datawrapper, we integrated a color blindness simulator, so no external tool is necessary."