Just thought I'd bring y'all's attention to this fresh WoB on Taldain's Darkside
Tattoos apparently, so we were all wrong on what the Skycolors manifested: not glow-in-the-dark people, eye colours or a literal limelight shining from the sky or aurora but tattoos.
Edit: Brandon might not exactly be talking about the Skycolors (like Breath vs Awakening)
And the Skycolors do involve bioluminescence and something like the aurora:
Prose stuff
and it could be a mix of UV interactions, bioluminescence and magic. The Skycolors varying between people definitely points to weirdness. ~ extracts & points from Mori on Discord