Try the color replace tool. It's with the rubber stamp.
Select it and in property inspectoe select the starting colo, the gray and the gold you want for the
In the To box I used FF9900, Tolerance of 14 and strength of 82, check colorize. Turned out pretty good.
Filters>Hue and Saturation
H - 37, S- 70, L - 0
Easy when you know how huh?
Liked the first way of doing this better than the second, seemed to have more control.
Glad it worked for you
Another method is to choose Adjust Color - Color Fill. Choose a gold color you like, and set the blend mode to Color.