When using

{
    "parent": "item/generated",
    "textures": {
        "layer0": "items/fish_egg_changer",
        "layer1": "items/fish_egg_changer",
        "layer2": "items/pufferfish_egg"
    }
}
 

Pufferfish egg is green when texture is yellow, and only when is yellow. Same with Salmon.

Negative colors dosen't help

Tropical fish and cod works normally

(fish egg changer is a name for empty texture that fills normal spawn egg colors)