Does this graph imply that the out of gamut cases only involve the red dimension?
@jackcsullivan Out of gamut cases occur when any of the dimensions are negative. I found an article about colorimetry and they had an example of negative blue to get wavelength = 610nm. https://medium.com/hipster-color-science/a-beginners-guide-to-colorimetry-401f1830b65a
How are negative values implemented, I would think that the least amount of a particular wavelength would be zero
You can always store the negative number. Gamut is important when you want to actually display the color on your computer screen. If the color is out of gamut then you can't physically show the color, because you can't emit a negative amount of a particular primary light.
Is it true that any color can be represented using RGB?
To ellenluo: From http://hyperphysics.phy-astr.gsu.edu/hbase/vision/colspa.html#c2 Yes, the primary colors (red, green, and blue) can be mixed to yield white -- therefore, they can be combined like unit vectors to form the entire color space.
There are colors not perceptible to humans that lie outside of rgb, and for say the srgb color space, it is missing certain things like certain saturations
Was interested in what "color" would be outside the RGB triangle, since it's something that humans define, and I found some interesting information from this post: https://biology.stackexchange.com/questions/56385/how-are-colors-outside-the-standard-rgb-color-scheme-perceived
so IF humans could view ultraviolet light, etc, how would that play into RGB and other color representations? What would the "primary colors" be for an animal whose visible light range is different?