Screen custom palettes with a colorblind simulator

Run a colorblind simulation on the chart before publishing when you choose your own colors. For example, inspect a screenshot or the live screen under simulations of the major color-vision deficiencies and look for categories that collapse into the same appearance.

Simulation can expose color collisions that are easy to miss during design. It is a fast screening step that shows whether the palette survives different kinds of color-vision loss.

Mechanism: A simulated view lets the designer see whether the current color encoding still separates marks under different color-vision conditions.

Evidence: The article recommends testing chosen colors with colorblind simulators, lists several ways to simulate all three types of colorblindness, and cautions that these previews are only approximate rather than a bulletproof final answer. (Muth, 2020)

• User Goal: Catch inaccessible color choices before release.
• Task: Palette review and chart QA.
• Data: Any visualization where color is doing identification work.
• Chart Setting: A chart image or live screen that can be simulated.
• Audience: Readers who may include people with color-vision deficiency.
• Success Criterion: Hard-to-distinguish colors are found before publication.

Break it when: You treat the simulation as final proof that the chart is accessible. Why: The article says the previews are not 100% correct and that everyone is different.

Sacrifice: You add an extra review step to the workflow. Risk: Simulation can create false confidence if you stop there. Mitigation: Add a second visual variable or ask colorblind people to review the chart as well.

Mistake: Skipping simulation entirely, or relying on simulation alone without any noncolor encoding. Why it fails: The first leaves color collisions undiscovered, and the second ignores the article’s warning that simulation is only approximate.

Failure Sign: You have not viewed the chart under simulated color-vision deficiencies. Quick Check: Run at least one simulation on the chart image or live screen and inspect whether categories remain distinct. Stronger Test: Simulate all three major colorblindness types and then confirm the design with a second encoding or reviewer feedback.

• Run a colorblind simulator on the current chart image or screen.
• Replace or separate any colors that collapse under simulation.
• Add position, shape, pattern, or line style if color alone remains ambiguous.
• Ask a colorblind reader to review the revised chart before finalizing it.