Minecraft wiki entry for Water, associated text: Warm oceans have a cyan color.
Lukewarm oceans have an azure color.
Cold oceans have an ultramarine color.
Frozen rivers and oceans have an indigo color.
Swamps have a green color.
Mangrove swamps ‌[upcoming: JE 1.19] have a teal color
Meadows have a vivid blue color
Regular oceans and other biomes not listed above have a blue color.