Sorry, not a copper red from what I can tell. The 1893 date of the cancel pretty much eliminates it from being that color which is reported to have been first issued in 1870.
Further, the stamp is heavily oxidized. You can tell this since the one color the stamp is printed in is not uniform across the stamp. In addition, a well-worn and badly stored stamp is the worst candidate for a color ID; too much has happened to it along the way to say that that is the original color.
EDIT: Hard to find ones that could be copper red, but this cover (not mine) is it, though I believe the color can also be in a narrow range around what we see here. There are later issues in brown red that are close, but the date (and other characteristics) says this is the copper red in the catalogs:
Posted 04/17/2019 11:24 pm
