Interesting image. I have never particularly liked the colored tinting they did back than as often times its poorly done and hides details. I would say based on his uniform this is an early war image of a Union soldier. The jacket is not a frock coat but more of an early war "state type" jacket. These were issued by several states but the largest quantities were from New York and Illinois if I remember correctly. The hat looks to be a "flat top crown" variety. A very popular hat of the time but probably more something a western soldier would have worn.
It has been my experience that usually when they did "tint/color" an image they did it to bring out detail that could not normally be seen very well in the original black and white. As with anything their are always exceptions to the rules. But more than likely this man had "Union" written on his hat and the tinter only highlighted it. With this in mind it would seem to support this being an early war image as often times such decorations that made you stand out as a target on the battlefield were dispensed with usually. Also I would take note that a tassel hanging over the side of his hat has been tinted yellow also indicating this man was probably a cavalryman. The belt and revolver would seem to support this as well.
Most of the early war roundabouts had 9 buttons, this one appears to only have 8 buttons. The epaulettes seem to be well made and not like the type with the edge turned under. Is that a cigar in his mouth?
He may have shown up for the photo shoot with few personal props. The photographer may have supplied the hat, the belt, the pistol, or ???? Hey, don't you remember the guy that came around the neighborhood with a pony, a camera , and all the bling to make a kid look like Roy Rogers or Annie Oakley?