The fluid present in between piameter and arachnoid is called cerebrospinal fluid.
Cerebrospinal fluid also known as CSF is clear and transparent flowing around the brain and spinal cord though in pictures we might see it as blue fluid surrounding the brain. . The fluid does not have any color. It is found both in brain and in spinal cord. It is produced by specialised ependymal cells that are present in choroid plexuses of the ventricles of the brain, and are absorbed in the arachnoid granulations.
The main function of CSF is to cushion the brain and protect the brain and spinal cord from from any type of external shock. Besides, that cerebrospinal fluid also circulates nutrients and chemicals filtered from the blood and removes waste products from the brain and spinal cord.