The blue horned sperm worm
A caterpillar that is pink and as a blue horn and found in France is called a hawk moth. These moths can grow very large.
Lime Hawk-moth Mimas tiliae
There are several types of caterpillar that match this description. They can have a white belly with a blue back and black markings.
The blue stripe caterpillar is commonly known as the "Hickory Horned Devil," which is the larval stage of the Regal Moth (Citheronia regalis). This striking caterpillar features bright blue and green coloration with distinctive horn-like projections. It is primarily found in the eastern United States and is often associated with hickory and walnut trees, which are its preferred host plants.
Not a Hawkmoth, this is a swallowtail butterfly caterpillar.
Really, nothing at all. They have the same colors, when they are caterpillars and when they are butterflies, so, (SOME) a caterpillar can be blue and white and the butterfly (COULD) turns out blue and white.
American Dagger Moth Caterpillar.... I found one in my drive way
it is a Lime Hawk Moth originating from England
Depending on where you live it might be some sort of Hawk Moth or a Fawn Sphinx. If you want to search for the Sphinx better enter "Sphinx kalmiae" otherwise most hits will be for the cat Sphinx. .
tomato horn worms.
normally the blue and red wires are hot white is standaed for nutral,
A white caterpillar that is not fuzzy typically has a smooth and shiny body with a solid white color.