Final answer:
The trichromatic and opponent-process theories are the two main theories of color vision. Evidence for the trichromatic theory includes the matching of colors using three primary colors and the existence of color blindness due to the malfunction of cones. Color blindness relates to these theories as it demonstrates altered color perception when certain cones do not function correctly.
Step-by-step explanation:
The two different theories of color vision are the trichromatic theory and the opponent-process theory. The trichromatic theory, also known as the Young-Helmholtz theory, asserts that color vision is achieved through the combined activity of three types of cone photoreceptors in the eye, each sensitive to a certain range of wavelengths corresponding to red, green, and blue. Evidence for this theory includes the fact that color photopigments have peak sensitivities that align with these three color channels, as demonstrated in experiments that measure the wavelengths of light that various cones respond to.
Color blindness is related to these theories in that it often results from a deficiency or absence of one or more types of cone photoreceptors. For example, red-green color blindness occurs when the red or green cones are not functioning correctly, which can manifest as difficulty in distinguishing between red and green hues. This form of color blindness provides evidence for the trichromatic theory because it shows that without the normal functioning of specific cones, color perception is significantly altered.
The evidence supporting this theory includes the fact that when people with normal vision view a certain color, they can match any color by adjusting the proportions of three primary colors. This matches the trichromatic theory's assertion of three color receptors. Moreover, people with dichromatic vision (a type of color blindness) can match any color they see with just two primary colors, which directly aligns with the concepts proposed by the theory.