Your cone cells (there are 3 types) are attuned to a small range of wavelengths to which they have a strong response, but the still respond to proximate wavelengths. The L type responds most to 564-580nm but has a normal distribution response ranging from 425-700nm. The M type peaks at 534-545nm but responds from 375-675nm. The S type peaks at 420-440nm but responds from 375-550nm.
Based on the ratio of activities from the three types of cones, your visual systems can integrate the information and give you the sensation of (sort of limited) color.
Slashdot Mirror
Your cone cells (there are 3 types) are attuned to a small range of wavelengths to which they have a strong response, but the still respond to proximate wavelengths. The L type responds most to 564-580nm but has a normal distribution response ranging from 425-700nm. The M type peaks at 534-545nm but responds from 375-675nm. The S type peaks at 420-440nm but responds from 375-550nm. Based on the ratio of activities from the three types of cones, your visual systems can integrate the information and give you the sensation of (sort of limited) color.