The reason dogs are afraid of blue water is the blue water affects the dog psychologically as dogs have different vision than humans.
The blue water can seen scary to the dog.
Many dogs will often avoid water that appears unusual or contains substances that they find unappealing.
Other factors such as scent, taste, and visibility play a role in how dogs perceive water.
Some dogs are also afraid of aluminum foil although not all dogs are afraid of aluminum foil.
The vast majority of dogs however will lose their mind and run away when they come up against aluminum foil or even hear the sound of it.
Most dogs will not get on surfaces or near areas where aluminum foil is because they hate the sound of it making noise when they walk on it.
You can keep dogs off furniture and things by placing aluminum foil in the area where they would have to walk.
You usually only need to leave the aluminum foil for a few days before the dog will start to avoid the areas.
It is the sound the foil makes as it moves and crumples, the sharp texture it makes under their paws, and the mirror like sheen across the surface.
This is what your dog reacts to.
Many dogs have sound phobias to loud noises like fireworks, thunderstorms, gunshots, and firecrackers as well.
There is even research that suggests noise phobias can be inherited.
And the herding dog breeds are particularly sensitive to noise phobias, perhaps because they're so attuned to their environment.