Our commander is spot on, especially concerning field/campaign clothing. Most officers wore the most rugged, but oldest clothing, if they wore uniforms at all! (Gen. Crook wore a canvas suit and pith helmet most of the time in the field. He was often mistaken for a correspondent or one of the other "hangers-on" by troops who had never seen him.) There are photos of 3rd Cavalry officers in a book called, "With Crook in the Black Hills" that show a mixed bag of clothing, including 1872 pleated sack coats, civilian hunting jackets, buckskin, etc. About the most common item of clothing would be officer's trowsers (spelling contemporary), with the 1-1/2" wide stripe down the seam, in the branch color. Even then, officers might also be seen with the Civil War-1871 cord, rather than a stripe, or buckskins or something they bought at the suttler's store!
Hope this helps, rather than confuses!
Your obedient servant,