Since their reapparence in the 1832 Regulations, the service chevrons were to be of the color of the branch in which the soldier was currently serving, whatever its previous service.
The War Service chevrons were introduced in the 1851 Uniform Regulations : "Service in war will be indicated by a light or sky blue stripe on each side of the chevron for Artillery, and a red stripe for all other corps, the stripe to be one-eighth of an inch wide." (The welt color was changed in white for the Arty in the 1872 Regs). Though not specified until 1885 (?), the color was that of the arm of service in which the soldier served at the time of the war.
Until 1881, the regulations mentionned the wearing of service chevrons only on the Dress coat. Between that year and 1885, it was permitted to wear the chevrons on overcoat and blouse, in fact sanctionning what was already done by the soldiers. It was again prohibited at the latter date.
Gold lace chevrons were introduced for the Dress uniform in 1884, sewn on a dark blue background ("the color of the uniform) for the service chevrons, and with a piping in the branch color for the War Service chevrons.
The service-in-war chevrons were awarded only when a state of war was declared, which was not the case for the Antebellum Indian wars. Otherwise, GO 49, 1885 read : "All soldiers who have served during the war of the Rebellion, and who were honorably discharged; all who served in the Indian campaigns enumerated in general orders from the Headquarters of the Army; and all who have served or may served in the Army of the United States in war, or such Indian campaigns approaching the magnitude of war, as may from time to time be so designated by the Secretary of War, are entitled to wear the "service-in-war" chevron."
What the "Indian campaigns enumerated in general orders from the Headquarters of the Army" are would need further research.
Except for the last remark, I hope this answer part of your question.
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