any color, depending on the Species
the giant squid can be any color because when it needs to hide it has to camouflage with the coral around it
transparent
RED
The skin is of a giant squid is covered in chromatophores, which enable the squid to change color to suit its surroundings. Like a chameleon
for camoflauge so the squid can change color to better blend into its surroundings.
pinkish red
black
light emerald green
color
It is the same color as Colossal Squid, because that is what is believed to have begun the tales from the sea.
Chromatophores are pockets of meyonin (similar to melanin in humans) that color the squid. These can grow larger or smaller to change the color of the squid itself. This can be used as a defense mechanism to camaflouge the squid from any harmful predators.