Valspar has teamed up with EnChroma to produce this short video. It shows people supposedly seeing colors for the first time thanks to the EnChroma glasses. EnChroma has a more technical breakdown of how their glasses work although it's a notch filtering system that purports to help users differentiate colors by blocking wavelengths that the cone's photopigments overlap on.
Unfortunately the glasses won't work for everyone but they do seem to have the greatest success rate with deuteranomalous and protanomalous users. I'd love to try them myself some day, videos like this certainly make me wonder what I might be missing.
I was recently asked by someone with a poor sense of smell and taste how horseradish tasted. How do you answer that? If he suddenly regained his taste I'm sure it would be much like if I could suddenly identify and see all colors, some things might make more sense and certain expressions that many take for granted would suddenly have meaning. My color blindness is certainly not as bad as it gets so I imagine the effect is even more profound for those who are more strongly affected.
For more on the project check out the Valspar Color For All site.