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.
• Dark mode support in macOS Mojave.
Ratings and Reviews
New Transparent Window mode is awesome!
I used a previous version of this application a while back to learn what my websites looked like with various types of colour blindness. I hard heard about it on a software podcast about accessibility. While it got the point across, that version was a little clunky with some issues with the infinite windows effect when you moved the mouse near the preview window. It was still functional but a little too jaring to be something that I'd open often.
I downloaded 2.0 today to show the colour blindness effects on a website to another software developer and was absolutely delighted with the Transparent Window mode. I certainly wasn't expecting clicks to work through the window, either, but the illusion was flawless. I really enjoyed using the new version and will probably use it much more often now. Thank you for making accessible web and software development easier.
One thing I kind of miss from the past version (if I remember right) was that there was a percentage of the population listed in the menu next to the type of colour blindness. That was a very nice piece of context for educating people on colour blindness.
Up to six family members will be able to use this app with Family Sharing enabled.