My New App: Colorblind Camera

This is my new app: Colorblind Camera. It is a universal app, but it obviously only runs on the iPad 2 because the iPad 1 lacks a camera.

What it does is let you view the world through the eyes of a person suffering from colorblindness. It would be a great app for graphic and web designers who need to make sure their products work well for everyone.

Here is a link to it in the store.

A couple of screens of the iPad version.



This is my first app and it was a lot of fun to make. I already have a couple more planned, so any comments would be appreciated. Always looking for feedback.

It is a pixel shader that is run on the input from the camera. The actual math is pretty simple, if you think about it geometrically.

Here is how it works. A normal person sees red as full red, blue as full blue, and green as full green. If you break down these as RGB values, you get these (obviously).

Red = (255, 0, 0)
Green = (0, 255, 0)
Blue = (0, 0, 255)

Now let's take Tritanopia, which is Blue-Yellow colorblindness. For someone with this, they don't see red as FULL red, they see it a bit differently. Using several sources on the net, these are what the colors red, green, blue look like to someone with Tritanopia.

Red = (255, 28, 0)
Green = (115, 237, 255)
Blue = (0, 127, 133)

Now, here is where the math part come in. If you think of the color spectrum as a 3D geometric space, where each of the primary colors are an axis in this 3D space, any color can be described as a point along those axis's. The 3D color space of a colorblind person is different, with their axis's pointing in different directions, at different orientations, etc, but the same rules apply. Any color they see will just be a point in their 3D color space.

Then, knowing this, we just need to transform the normal color space into the color space of a colorblind person. Luckily, linear algebra makes this pretty easy (it is just a single matrix/vector multiplication). We then apply this same transform to every pixel from the camera, and you then get your output.

Does that make sense?