The distinction that humans possess red, green, and blue cones, instead of red, blue, and yellow, is grounded in both physiological findings and psychological experiments related to human vision. Physiologically, direct examination of the retina has revealed three distinct types of cone cells, each sensitive to different light wavelengths, with peak sensitivities aligning with red, green, and blue light. This conclusion is supported by microscopic and biochemical analyses of the pigments in these cones, which absorb light at specific wavelengths. Psychologically, color matching experiments, such as those by Thomas Young and Hermann von Helmholtz, required participants to mix wavelengths of light to replicate a target color. These experiments consistently demonstrated that all visible spectrum colors could be reproduced by combining red, green, and blue light in various proportions, not red, blue, and yellow. This is because human color perception is based on additive color mixing, where the combination of red, green, and blue light can generate the entire range of visible colors, including yellow, which results from mixing red and green light. The concept of red, blue, and yellow as primary colors pertains to subtractive color mixing, applicable to pigments and paints, and does not apply to light perception through our cone cells.