No, I am talking about more color discrimination within the visible range.
So much like a red-green color blind would normally see red and green as the same color, but with special glasses on (if they worked) they would appear as different colors. But they arent seeing UV or infrared.
Similarly if we could make humans into tetrachromats (equivelant to having one additional color discriminating receptor) then two colors that appear the same (say they both look red) would appear as two different colors, red and some new color you had never seen before. You arent seeing a new part of the spectrum, you just have high color discrimination.