Re: yellow with no green
An interesting revelation came to me when I really dug into the idea of color perception many years ago. The short of it is simply that light does not come in only 3 colors (red, blue, green), but in fact comes in a wide range that is interpreted by our brain and the cones in our eyes.
So not to confuse the idea of color for anyone new, but RGB systems are but one system used for color representation and does have limits. Many pigments exhibit wavelength reflections that are quite difficult to capture by photograph or other reproduction methods. The cones in our eyes actually each respond to a range of wavelengths, these overlaps have color associations that are sometimes labeled as “red, green, and blue” respectively, but actually peak in wavelengths associated with colors we would not think of as red, green, and blue actually. It would be more accurate to think of the cones as short, medium, and long wavelength detectors. Some people are even gifted with an extra vision cone (possibly my wife), and see a wider range of yellow and orange colors.
As noted above though, yellow pigments tend to have a large enough reflectance of wavelengths that our brain associates with the color green, thus mixes with most colors that are darker in value to produce a green color. Personally, I consider the “primary” yellow pigments to be quite green leaning, and generally reach for a slightly more orange leaning yellow for most of my work (just my tastes).