Yes it is normal. This is algae growing on its shell. Grab a toothbrush and some warm water [not hot as to NOT burn the turtle] and gently scrub the shell, it should come off eventually.
The small green blotches on a painted turtle's shell are often a sign of algae growth. Algae can accumulate on the shell when turtles bask in sunlight or swim in water with high nutrient levels. While this is typically harmless, excessive algae can indicate poor water quality or environmental issues. Regular cleaning and maintaining a healthy habitat can help manage this growth.
Give Your Turtle a BathSoak your turtle in a tub of warm water or hold your turtle underneath running water.Gently rub the shell with a soft washcloth. This will remove most of the dirt and algae. Small bits of the shell may flake off in the process. This is part of the normal shedding process.Scrub your turtle's shell with a soft brush. An old toothbrush works quite well. Lightly scrub away the larger portions of algae but there's no need to scrub the shell completely clean.Check the shell for infection after most of the algae is removed. Soft spots, or spots that smell rancid, are an indication of shell rot and should be treated by your vet as soon as possible.If no problems are detected, you may then apply an application of turtle shell conditioner. This specially-formulated conditioner helps to revitalize dry or brittle turtle shells and can be purchased at pet stores.This answer was copied directly from the web-site in the related link.
The green sea turtle got its name from the greenish color of the fat beneath its shell, which is a result of the turtle's herbivorous diet, primarily consisting of seagrasses and algae. This coloration contrasts with the turtle's dark, mottled shell. Unlike other sea turtles, the name specifically reflects the distinctive hue of its body fat rather than the color of its shell.
The green sea turtle gets its name from the green-colored fat tissue under its shell. The fat has a green color because the adult turtle's diet consists of seagrass and algae.
A calipash is an edible greenish material found underneath the upper half of a turtle's shell.
An alligator could eat a turtle in its shell, and a shark could eat a sea turtle in its shell.
As with any turtle the turtle shell is called CARAPACES.
A sea turtle has an external shell.
If a turtle does not have a shell, it can be both naked and homeless.
It is ok to carry your turtle but I don't recommend that you do it often because it can stress on the turtle. If you are going to carry the turtle make sure that all of its legs and shell are supported. It wont like the feeling of hanging in mid air.
i think it would grow with the turtle and then when it is an adult the shell would be fully grown