It's hard to say because I know how digital pictures can have their color out of wack and make a coin or medal look like just about anything. Here is pristine example of the medal in its issue color. This piece was housed in an aluminum case. The obverse was designed by Augustus St. Gaudens, and the reverse, much to St. Gaudens shagrin, was by Charles Barber. This is fairly common medal. It was issued to every person, company and group who had an exhibit at the 1893 Columbian Exposition. Each piece was had the name of the recipient on the reverse at the bottom of the square. The piece above when to "George Whiting." Your piece was awarded to the "Newton Machine Tool Works." St. Gaudens was angry because his original reverse was replaced by Barber's design, which he thought was inferior. Here's St. Gaudens' design. The Expo leadership did not like the appearance of nude man on the reverse. The model for that design was Homer St. Gaudens who was the artist's son. I know I didn't give you answer your question, but I have seen quite a few examples of this medal. I have never seen one that was gold plated, at least from the time it was issued.
