@prabhakar: We can aalso match a shade exactly by a correct combination of basic colors.
Well ... sort of -- maybe -- it all depends. Most of us have three different types of color cones/receptors, so the mixing of CMYK pigments works well for us (similarly for mixing RBG light) -- but some people have four types of color receptors, and I think they do not get as good an experiance from the standard image generation techniquies we use. Check out the Tetrachromats, Pentachromats, Etc. topic in my paper on color vision.
But I am talking about the production of the desired colors - depending upon the resolution available we can create required no of shades of colors as we want. We can aalso match a shade exactly by a correct combination of basic colors.
Similarly even if we may not know how a partcular smell is perceived by our sensory system, we may be able to atleast reproduce a smell based upon its recipe ( the percentage of the basic components). This will enable us to transmit the Smell alongwith picture , video.
In Virtual reality context , this is the important area that we are still missing, in my opinion