Here is an image of an Imperial agent wearing Mark VII Katarn armor. A specific version of Katarn armor, known as Katarn armor Mark VII, saw action throughout the duration of the Galactic Civil War.
Featuring a black base color accented with green-yellow highlights, this particular model of Katarn armor remained in service with the Imperial Military longer than any other variant. It seems that it was not typical for members of the Stormtrooper Corps to be issued this armor; rather, it was more often acquired by individual operatives.