Subnautica drops the player into the deep alien ocean of planet 4546B — a descending column of water from steel-blue shallows into near-black abyss, threaded with bioluminescent flora. The signature is glowing aquamarine cyan against deep-water blue.

The interface reads as the survivor's PDA dive computer: cold ocean panels lit by cyan luminance, with a single warm orange HUD accent cutting through. Depth is the organizing principle — every layer descends from shallows toward the dark.