Minecraft wiki entry for Unused_textures, associated text: Reimplementing and actually using this file for the majority of biomes, like is done for grass and foliage, with swamps and possibly a few other biomes being the only remaining special-cased biomes, would likely resolve this issue in its entirety, as there would no longer be a need to specify water colors in biome json files; a blank entry would cause the game to seek out a value from the color map, which is what happens currently for grass and foliage.