Works as promised. Very good teaching tool.

Excellent add-on!

I'm a front-end web developper, and since Color Oracle software ceased to function with my setting ("recent Ubuntu versions are not supported"), it was really difficult to test webpages I worked on… So I'm grateful that this add-on exists.

And it's very comprehensive: proto/deuterano/tritanopia & -anomalies, cataract, nystagmus, low contrast…

Great extension for developers.