Why is white matter of the spinal cord white?

White matter is one of the two components of the central nervous system and consists mostly of glial cells and myelinated axons. The white matter is white because of the fatty substance (myelin) that surrounds the nerve fibers ... White matter in the spinal cord functions as the "wiring"; primarily to carry information.

The white matter is white because of the fatty substance that surrounds the nerve fibers.