There was more than one 1st South Carolina infantry regiment: Gregg's regiment, Hagood's regiment, 1st SC Regulars, and Orr's 1st SC Rifles.
You mention green trim. The Rifles started out with a dark blue uniform trimmed in green (green being traditional for rifle units), however many ended up being manufactured in gray, possibly to conform to CS uniform regulations, though still maintaining the green trim. That uniform would have only been in use in 1861, possibly into early 1862. In August 1861, Col. Orr commissioned a more suitable uniform for the regiment consisting of a "thick heavy woollen plains or jeans coat, overcoat and pants." The ladies' aide societies making these uniforms were advised to "Dye the cloth brown.... from the trees and shrubs of our own forests." This is according to Ron Field's The Confederate Army, 1861-65, Vol. 1.
Frock coats were also issued by the South Carolina state quartermaster through 1862 (some with trim or facings and some without), but they were later replaced with shell jackets by 1863. South Carolina troops serving in the ANV would have also been issued uniforms from the Richmond Depot.