From The Institute of Heraldry:
Green was prescribed as the first Medical Department color in 1847 when the sash for Medical Officers was described. The green was established in the insignia of the Hospital Stewards uniform on 31 October 1851 and in 1857 the green was piped with yellow and the pompon was topped with medium or emerald green. Later the pompon was green piped with white until 1902 when the maroon color was adopted. In 1903, the Hospital Corps chevrons were maroon piped with white. Maroon and white were established for all branches of the Medical Department by the uniform specifications dated October 1916.
Medical Director Bee's Brigade - 150th First Manassas
Medical Director Evans' Brigade - 150th Leesburg
Medical Director Valley District - 150th McDowell
Chief Surgeon of Division - 150th Seven Pines/Seven Days
Chief Surgeon of Division - 150th Sharpsburg
Chief Surgeon Heth's Division - 150th Gettysburg