Mammals generally have red-green color blindness, which leads to an inability to see the hunter orange as a distinctive color. The ancestors of mammals, though, did have more color receptors (and marsupials keep the full allotment). Primates acquired a third color receptor through gene duplication (not resurrection of the ancestral color detector).
So, to acquire color vision of the type required for deer to see orange would likely require a gene duplication and subsequent mutation. Gene duplication isn't an incredibly common thing, especially at a given locus and is certainly not the type of thing one should expect in a few generations. And even if that duplication happens, there is an additional mutation needed (which is probably not as difficult to get).
I'd assume if the duplication and mutation happened, they would spread fairly quickly given the utility in the modern populations. But don't expect such to happen any time soon.
So, to acquire color vision of the type required for deer to see orange would likely require a gene duplication and subsequent mutation. Gene duplication isn't an incredibly common thing, especially at a given locus and is certainly not the type of thing one should expect in a few generations. And even if that duplication happens, there is an additional mutation needed (which is probably not as difficult to get).
I'd assume if the duplication and mutation happened, they would spread fairly quickly given the utility in the modern populations. But don't expect such to happen any time soon.
