The Snap-On balancer instruction booklet at the garage I hang at says that the stick on weights installed on the inside of the wheel hub are harder to balance with as they are closer to the rotational center of the wheel and have to be more exact. The weights on the inside wheel lip only is called a static balance. Both of these are not as good a balance as weights on both inside and outside wheel lips which is called a dynamic balance. I've tried all three and the dynamic is the best! As for painting your weights, the weights we use for aluminum wheels are painted (sort of a silver gray color) and the paint holds on them so I think if you clean the weights good (carb. cleaner, mineral
spirits, etc.) before painting them, you should be fine!