What it does
Sim Daltonism is a colour-vision simulation tool for Mac and iOS. The Mac app filters a region of the screen, while the iOS app uses the camera. Both are intended to help visualize several types of colour-vision difference.
When two chart series differ only by hue, a simulation can reveal a distinction that may be difficult to see. Sim Daltonism lets you inspect a region of the Mac screen or a camera view on iOS through colour-vision filters.
Use the preview as a reason to improve the design, rather than as a pass or fail certificate. Add direct labels, different line styles or another visible cue so the meaning does not depend entirely on colour. A simulated view is a design aid; it cannot reproduce every person’s visual experience.
Strengths
- Mac screen filtering and an iOS camera view cover different contexts.
- Several colour-vision simulation types are offered.
Watch out for
- A simulation cannot represent every individual’s vision.
Best for
- Checking whether a design relies too heavily on hue
Sources
- Sim Daltonism (Oct 25, 2026)