I have played this game a couple of times and I believe the best way to do it is to prime your bolts lightly and either put one light coat of paint on them or none at all. After install, touch them up with a small brush with un-thinned paint. If you fully paint them that paint will chip or curl up and then you have that problem. Fully painted bolts are also larger and don't want to fit in any socket. Touching them up with a brush won't really show due to the finish and contour of the bolt heads.