When the sun's down
Nocturnal rainbows soar in the air so high
from Hopsin – Nocturnal Rainbows Lyrics on Rap Genius
Meaning
When the “truth” isn’t there, impossible things are molded into the truth.

Although this metaphor relies on rainbows being impossible at night, that’s actually not the case. Real “nocturnal rainbows” called moonbows are produced by light reflected off the surface of the moon rather than from direct sunlight.
To help improve the meaning of these lyrics, visit "Nocturnal Rainbows" by Hopsin Lyrics and leave a comment on the lyrics box