Gray matter is to as white matter is to?

Gray matter is unmyelinated and White matter is myelinated

White matter is a dense collection of myelinated fibers and cell bodies while grey matter is unmyelinated fibers.

The brainstem is composed of both white matter and grey matter. However, the brainstem is predominantly white matter, made up of myelinated axons.

Yes. Your cerebellum is actually made up of very tightly folded outer layer of grey matter, and you can find the white matter lies underneath it.

gray matter