I count seven on the Army List as of Q1 1861, but reading the Army List was a pain and I may have missed some.
Colonels with a higher brevet rank
John Garland
Colonels by rank
Thomas Lawson
Thomas Fauntleroy
Phillip St. George Cooke
Matthew Payne
Washington Seawell
Colonels by brevet only
RE Lee
Colonels with a higher brevet rank
John Garland
Colonels by rank
Thomas Lawson
Thomas Fauntleroy
Phillip St. George Cooke
Matthew Payne
Washington Seawell
Colonels by brevet only
RE Lee
Comments
https://www.nps.gov/rich/learn/historyculture/-if-virginia-stands-by-the-old-union-robert-e-lee-resigns-from-the-u-s-army.htm