The Dravidians originated in Africa. They used the same red-and-black ceramics.As Africans. Red and Black pottery dates back to 4000 BC in Africa. It was used by many Kushite nations like Kerma, and C-Group.
B.B. Lal (1963) proved conclusively that the Dravidians were genetically related to the C group of Nubia, given the fact that both groups used 1) a common BRW, 2) a common burial complex incorporating megaliths and circular rock enclosures and 3) a common type of rock cut sepulchre.
The BRW industry diffused from Nubia, across West Asia into Rajastan, and thence to East Central and South India. (Rao 1972:34)