- Could it be theoretically possible that we could discern more colors in a wider space, given that "the larger gamut will necessarily represent more distinct, humanly-perceptable colors than a smaller gamut."
I think you got the crux of the problem right here Slodoban.
If you can define individual humanly-perceptable colors in terms of a closed volume in LAB space, then the answer has to be
yes. The volume doesn't even have to be uniformly-sized throughout the space, it just needs a clear boundary and a defined volume. If you do that and you have a positive, defined volume in LAB space for individual colors, then clearly a larger volume will, in theory, hold more of these. You can even go through the trouble of not counting these units when they fall outside the spectrum.
The problem is that it is quite difficult to define these volumes of humanly-perceptable colors in LAB space. Although it's in the right spirit, ∆E doesn't work.
The first problem you run into when trying to define these volumes is one of definition. We've decided that a unique color needs to be discernibly different. So even if the numbers are different, they don't count as uniques colors if they look the identical, right?. So this would count as one color even though the image is made of two color values:
![](http://i.imgur.com/aNopWOX.png)
But if we are going to be strict and define colors by human perception, then
how many greens are in this image?![](http://i.imgur.com/3KQ0CSu.png)
The numbers say one, but my eye says more than one. So how many do we count it? Regardless of how you defined the volumes above, all these green will fit on one point in LAB space, yet by our own definition there is more than one color here. That's a paradox that we can't solve using our current colorimetry (although research on color appearance models is working on it).
You now might be tempted to change your definition of color to exclude the messy realities like simultaneous contrast and decided matches under laboratory conditions with set surrounds and white points, but then your volume calculations only work in the laboratory and you're back in a lot of ways to where you started.