So, as many people know, humans have three cones cells, enabling us to see three distinct "primary" colors, which may combine to form the entire spectrum that we are capable of seeing. Meanwhile, many other animals have four or more cone cells, enabling them to see an even broader, or more well-defined, spectrum.
Now, digital cameras typically record the light using an array of photosensitive "pixels". The pixels are generally arranged in groups of four, with two specialized (using filtering materials) for green, one for red, and one for blue. The intensities detected by each pixel and then converted to an RGB file using some algorithm. The intensities recorded by each specialized pixel can be mapped to the hue spectrum below.
This is what we generally want, as the resulting image makes perfect sense to our eyes and is sufficient to record a scene for most intents and purposes. But why must we restrict a camera to capturing and recording light the way humans see it?
Let's say we changed the filters over the photosensitive "pixels" to optimally admit different wavelengths, particularly ones that we don't normally see, or ones closer together in a specialized color range that would provide more detail. From there, we could stretch the hue spectrum, with 0/360 being the first color, 120 being the second color, and 240 being the final color.
I'm very curious to see what the result of this would be, if for example we picked the wavelengths of 800 nm, 400 nm, and 200 nm in order to see a little bit more into the infrared and ultraviolet. Or, if we had a collage of something that appeared blue, we could choose the wavelengths of 450 nm, 475 nm, and 500 nm in order to distinguish similar shades more easily. Another possibility would be to detect four different wavelengths and map these onto the hue spectrum. This would allow for something like "tetrachromatic" photography.
Here is a mockup of what one might expect (changed to better reflect the question):
Here are some things to answer:
Is this already being done? If not, why not? (I've seen ultraviolet and infrared photography before, but it is usually black / white or black / magenta. Why use one dimension and why not stretch the spectrum?)
What exists in terms of consumer technology to take images this way?
Are there limitations in technology to what wavelengths can be captured?