If you are colorblind and wanted to know how about what colors you might not be seeing in the world, this is the app for you.
You can pick a color from the camera. The app will then use a black and white region on the camera feed to indicate how similar things are to that particular color. White being most similar and black not being similar at all.
The app also has a screen where it converts a region of the camera to black and white (averaging the red, blue and green), you can then toggle on/off each channel, which will affect the brightness of the black and white. It's a quick way to know for example, how much red is visible. Toggle the red checkbox on and off and you'll notice a change in brightness.
When selecting a color from the camera. The closest color name is also shown so you get an idea of what the color you're comparing is as well as the percentage or red, blue and green.