One thing to point out is that the circadian rhythm is (largely) not directly influenced by the cones or rods (to our current knowledge). It is a third set of p

One thing to point out is that the circadian rhythm is (largely) not directly influenced by the cones or rods (to our current knowledge). It is a third set of photoreceptors, the ipRGCs, which detect blue/green light and provide input to the circadian rhythm in the pineal gland/suprachiasmatic nucleus. The gray area is the sensitivity of the ipRGCs. Also, that's a good point about the colors vs. dotted/dashed lines. I'll look into that, thanks!