[bhlaazep] Color separation for colorblind

Create a mobile app to assist the colorblind, using the smartphone's camera to examine objects in the real world.  This should be easy and probably already exists.  What image transformations of what the camera sees would be most useful?

Easiest would be to present 3 images all in black and white for the red, green, and blue channels.  Other color separations, e.g., CMY?

For the common red-green colorblindness, maybe just 2 images: red blue and green blue.  Not sure what two colors to use for the processed images, perhaps the original colors.

Or, just 1 image, but with the hue component rotated (say) 120 degrees.

Or go the other direction: provide a tool for normal people to see or distinguish colors they cannot normally see, e.g., tetrachromancy.