From the perspective of a color blind person, some colors are impossible to distinguish. Sim Daltonism lets you visualize colors as they are perceived with various types of color blindness.
Move the Sim Daltonism window over something on the screen and see what it looks like with a color blindness. With this app you can check the accessibility of websites and other user interfaces, make your visual designs better for color blind people, or just play around to better understand how various color blindness types affect color perception.
The Filter Window
The Sim Daltonism window acts as a filter for what is under it. You can click inside and manipulate windows from other apps that are located under it.
But you can change this so the filter window follows the mouse pointer, displaying the area around it. This makes it possible to view the filtered image alonside the unfiltered one.
Sim Daltonism is fast enough to filter a video in real time or to have many filter windows active simultanously.
If needed, you can reduce or increase the refresh speed to save energy or improve responsiveness.
Sim Daltonism can simulate the vision of many forms of color blindness:
• Deuteranopia (no green cones)
• Deuteranomaly (anomalous green cones)
• Protanopia (no red cones)
• Protanomaly (anomalous red cones)
• Tritanopia (no blue cones)
• Tritanomaly (anomalous blue cones)
• Partial monochromacy
Note that the colors shown are only an approximation. Color blindness varies from person to person and the simulator cannot represent everyone’s vision. Many other factors can affect the results, such as the automatic white point calibration of the camera. Nevertheless, Sim Daltonism is a good tool to better understand color blindness.
Sim Daltonism is open source and is also available for iOS.
• Corrected an issue preventing the window from appearing over full screen applications in macOS 10.10 et 10.11.
Ratings and Reviews
This is a godsend... needed to review the screen shot for a Excel tool for GPs, and was dreading having to compare every colour (which was looking like the only way). Because it filters the whole image it's easy to screenshot or show onscreen to developers why you need them to alter the colours. I've already recommended this to a number of people. It's also totally intuitive to use. Thanks for makiing it available
I needed a tool to quickly check a design (and future designs) and this was brilliant. Download, point and check through. Really helpful!
Useful for web design and any graphical work to check that the end product will be readable to everyone.
Up to six family members will be able to use this app with Family Sharing enabled.