Assume that people with normal color vision perceive all colors on a display as the cubic region of a color space like opponent color space, shown in the following figure (a). Then people with color blindness perceive the same color as the region near the two-dimensional plane, shown in the figure (b) or (c).
Protan and deutan observers can perceive luminance-element and yellow-blue-element from original colors. And they see changes by Red-Green transform which reflects red-green-element on luminance-element. As a result, they could obtain three-dimensional information.
The following figure shows how Visolve Red-Green transform transforms the colors in the color space. (It is a cross-sectional view of the color space viewed from the direction of the yellow-blue axis.) In colors of the same brightness, redder colors are transformed to brighter, and greener colors are transformed to darker.
|Location of original colors||Location of transformed colors|
Blue-Yellow transform transforms colors in the same way as this with respect to the luminance and yellow-blue axes.