I think it's got character just the way it is. You could wrap the handguards and stock so that it wasn't such a stark contrast between the guts and the grips.
You could also get it cerakote'd/refinished. Here's a few threads I found on Arfcom about matching the O.G. Colt finish on retro rifles.
Seems that Norrell's Grayish-Black Flat moly resin is the best match.
Not meaning to double-tap, but couldn't get this last link to work in my O.G. post. Anyway, here's the site.
The color you'd need even has "COLT" in the name.