點解L-cones are often referred to as the red receptor?

"red receptor"係咪即係yellow-green receptor?
Peak sensitivity of "red receptor"is in the yellowish-green region of the spectrum, 咁點解L-cones會被人叫做"red receptor" (or stimulated by red parts of the visible spectrum)?

L-cones... range:500~700nm...
是否因為佢可以被wider range of wavelength of red light (大約6百幾nm至700nm)stimulate when comparing with range of wavelength of yellowish-green lights, 所以被人叫做"red receptor" ?

好混淆...