Modern cities are turning white. The switch to LED streetlights has killed the night.
The Sodium Vapor Era
Remember the orange glow of the 90s and early 2000s? That was high-pressure sodium. It emitted a very narrow spectrum of light (around 589nm). It turned the world into a monochrome sepia photograph.
The Blue Hour
Now, with 5000K LEDs, the night is clinically accurate. We can see colors, but we lost the mood. The 'Blue Hour' used to be a magical transition time; now it's just when the sky is blue and the ground is... also blue-white.