If theres any body of water thats landlocked or completely surrounded by one single biome, then it should correspond to the theme of that biome.

For example:

Grassland biome - regular water

Savannah biome - brown, muddy water

Mushroom biome - murky water

Enchanted biome - shiny, sparking regular water

Corrupted biome - murky water with bones floating around

Swamp biome - whole biome needs to be reworked to look more like an actual swamp, imo

Infernal biome - lava instead of water

Jungle biome - very clear, light blue water

Candy biome - soda instead of water

Arcane desert biome - very clear water, light blue water

Crystal biome - murky, sparkling water with lots of minerals in it

Lemon biome - lemonade instead of water

Permafrost biome - iced over if its shallow ocean; murky bright blue water if its close or deep ocean

Let me know what you think