William W. Colston, 68, of Locke Cuba Road, retired employee of General Motors Corp. in Memphis, yesterday at his home. He leaves his wife, Mrs. Louise I. Colston; three sons, W.H. Colston, D.W. Colston, and P.R. Colston, all of Memphis; three sisters, Ethel Colston of Bonicord, Tennessee, Mrs. Hygiene Thomas of Dyersburg, Tennessee, and Ruth Colston Fisher and one grandchild. Memphis Funeral Home on Union.