[jdavis7600]

If you're only interested in coloring only the tops/ends of the lug bolts, and not also the sides, it'd be a lot easier and less expensive to rattle can them.

If you do powder coat the tops/ends and also the sides of the lug bolts, you might expect the powder coat's bond to the bolts to fail due to the compression forces acting on the bolts when they're tightened or loosened.

If the powder coating is applied too thickly, your 15mm, 17mm, or 19mm socket may no longer fit your lug bolts, or may damage the coating when it's pushed onto the lug bolts.

Also, if you have locking lug bolts into which the special wrench tool is inserted, powder coating may make subsequent insertions difficult, if not impossible. Same may also occur if you have spline locking lug bolts.