Yes, they do, after the photoreceptors. Those CIE colorspace curves aren't biology, and shouldn't be interpreted as such.
LMS colorspace is the (currently understood) biological colorspace [1], and contains inhibitions, from the opponent process [2] found in the meatware [3]:
red-green: L - M
blue-yellow: S - (L + M)
This contains a nice introduction to biological colorspace [4].
Oh I was referring to the response of the cones itself (not the response after the opponent process). I was under the assumption there's no measured curves for the responses after having gone through the opponent process in the neuron-layer(?), so the graph and caption were conflating the response of the cones with color matching functions.
> This contains a nice introduction to biological colorspace
Looks like an interesting read, thanks for sharing!
> This contains a nice introduction to biological colorspace
Looks like an interesting read, thanks for sharing!