This may be one of those "art versus reality" questions...
Those bridges were factory-made stock equipment items. I would expect that they came fully-painted without any naked wood showing - they almost certainly came painted in the prevailing regulation base color of the issue year (blah. I LIKE the wood look!).
So... I would suggest painting them thusly - with your vehicle base-color. BUT, as these were made of wood with metal fittings, a used bridge could have both chipping and metal-exposure on those parts AND gouged up wood on those areas!
Also, IF you are doing the track up with a camo scheme, which likely was applied by the crew or a small front-area shop team, you might consider whether your "paint crew" removed the bridges before painting on the camo, or whether they simply sprayed over everything. You could plausibly have bridges in base color while the track is camo'd.
Just my opinion and suggestions, of course!
Bob