From the article, "..we also noticed something rather curious: the colours that best passed through the glial cells were green to red, which the eye needs most for daytime vision. The eye usually receives too much blue – and thus has fewer blue-sensitive cones."
"Light from the Sun is strong in blue, short wavelength light ..when it comes in the evening or during the night, it fools the body into thinking it’s daytime. We now know that this bright blue light has the strongest effect on lowering melatonin during the night. Your tablet, phone, computer or compact fluorescent lamp (CFL) all emit this kind of blue light."
From another article on the same site, https://theconversation.com/a-dark-night-is-good-for-your-he...
"Light from the Sun is strong in blue, short wavelength light ..when it comes in the evening or during the night, it fools the body into thinking it’s daytime. We now know that this bright blue light has the strongest effect on lowering melatonin during the night. Your tablet, phone, computer or compact fluorescent lamp (CFL) all emit this kind of blue light."