Edit:<p>tl;dr - color is a 3D space. Colorblind people can only percieve two of these. This device may change the projection of the 3D space on their 2D space, but it will not magically make the third dimension pop out.<p>-- original post, a bit less synthetic.<p>Color is a 3D space (wherever you chose to put the axes, RGB, HSL...) because we have three subtypes of color-related light detectors, called cones, in our retina (there are more photosensitive cells, but they aren't involved in color).<p>Each cone is sensitive to a range of the visible spectrum, with peak sensitivity respectively in what we call red, green and blue. These ranges are overlapping, though, which allows our brain to interpret monochromatic light correctly by weighting the response of each type of cone.<p>See [1] for a schema and a more thorough explanation.<p>Note also that magenta exists as a color (ie unique subjective experience), even though no monochromatic light can evoke it. You get it by stimulating the red and the blue cones, sparring the green one.<p>All of this to say that with two cones, you're stuck in a 2D space of color blindness.<p>This tool may help colorblind people to get a different projection of the 3D space in their 2D detection field, but they will not be able to perceive the 3D space at once.<p>--<p>For those who didn't get their dose of photoreceptors trivia:<p>The retina also contains another type of detectors called rods, which are much more sensitive to light than the cones, and is involved in both day and night vision whereas the cones are only stimulated in daylight This explains why you don't percieve colors in the darkness.<p>At last, the recently discovered melanopsin containing ganglion cells are involved in the circadian cycle and other light-related acivity in the autonomous nevous system.<p>--<p>[1] <a href="http://www.unm.edu/~toolson/human_cone_response.htm" rel="nofollow">http://www.unm.edu/~toolson/human_cone_response.htm</a>