^^
All of the above mentioned programs have other filters as well. Since the additional information is there and it's just that you don't fully perceive it, you can partially detect it via transforms. Facet's original reply probably wasn't particularly well thought out
qua what is immediately useful for those who -are- colorblind, but you may be able to recover some information via gamma or contrast filters.
Maybe a filter that transposes RGB channels would be useful to you (I'm not sure, as I personally don't have any known degree of colorblindness) -- I don't know about Photoshop, but both GIMP and GPick implement display filters via simple plugins, so such a filter would be a fairly straightforward thing to write.
I wrote the
Quantization filter for GPick myself, and of the 100-odd lines of that, the core filter is implemented in only 6 lines -- much of the rest is just boilerplate.
GIMP's
Gamma filter is a good example of a simple GIMP display filter, and it's similar in complexity -- more boilerplate, but the core behaviour is implemented in ~12 lines.
It's unclear whether Photoshop supports proper display filter plugins, or if it's limited to the hardcoded behaviour of the color-proofing options.
Fortunately, given color proofing functionality and an appropriate target ICC profile, it is possible to perform arbitrary transforms of the image colorspace (as in the above example of transposing the RGB channels), but I don't personally understand how one constructs an appropriate ICC profile. Probably investigating littlecms2 would be enlightening in that regard.
