I was told that the kind of resin used makes a difference. I used fiberglass liquid resin that contains polyester resin and styrene, basically the kind used for cars. You can paint them with an epoxy paint, but, if it was me, I would mix up the same fiberglass resin you used to coat them with and add fiberglass color pigment to the resin. Mix thoroughly, add hardener and apply with a brush. Usually two coats of resin will color it completely.
Color pigment is available in basic colors at major outlets.
Try where you bought your resin. This will provide a very durable finish, much more abrasion resistant than paint. Given the wear and tear on floorboards, I think it would be a better finish. All Rights Reserved.