Snowpiercer is Bong Joon-ho's 2013 thriller set aboard a perpetually circling train carrying humanity's last survivors through a frozen Earth. Shot by Hong Kyung-pyo, the tail section is grimy frostbitten blue-gray steel lit by flickering bulbs, escalating car by car into gaudy saturated color before the sterile engine.

This design system distills that cold-to-warm class gradient into a dark, riveted industrial language: steel-gray grounds, condensed transit-warning signage, and front-car red and amber reserved strictly as accents that pierce the gloom.