A closer look

It turns out sensory deprivation in a tin can is bad for morale, so the Soviets threw up a coat of lime green. While the exterior of nuclear subs is coated in black acoustic tiles to remain stealthy, the interiors of Russian submarines are famously painted a harsh turquoise/green color. Psychologists theorized that this specific color scheme reduces stress and keeps the crew calm during months submerged in the claustrophobic depths.