Though in very low light (such as moonlight), all three types of cones are equally useless and you&#x27;ll change from photopic vision [1] to scotopic vision [2]. In that case, your eyes will be more sensitive to blues than they are to reds, but you can&#x27;t discriminate between colors at all.<p>For the scenario of a neon sign at night, you&#x27;re probably in the mesopic vision [3] range, which is a somewhat fuzzy mix of the two. If they&#x27;re all putting out an even number of photons, the blue sign would still not be as visible.<p>An interesting real-world experience I had with this: I was driving at night and saw the indicator LED on my phone flashing blue out of the corner of my eye. When I stopped and checked it, it turned out that it was actually yellow. Even when something&#x27;s bright enough to trigger a color response in the center of your vision, it may be a primarily cone response toward the outside of your vision, which is strongly dominated by rod cells [4].<p>[1] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Photopic_vision" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Photopic_vision</a><p>[2] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Scotopic_vision" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Scotopic_vision</a><p>[3] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mesopic_vision" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Mesopic_vision</a><p>[4] <a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Photoreceptor_cell#&#x2F;media&#x2F;File:Human_photoreceptor_distribution.svg" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Photoreceptor_cell#&#x2F;media&#x2F;File...</a>