Generally speaking, black doesn't work well under NVD observation. The answer is to either not worry about it, or to find a way to cover as much as possible of the black surface of the carrier with fabric/velcro/pouches that are less visible under NVD observation.
For the most part, this ought not be too difficult, as long as lightweight, non-bulky items are used, and one avoids the temptation to fill excess pouch capacity. Even the shoulder straps of the black PC can be retrofitted with padded, slip-over sleeves.
One can wear a small pack/hydration carrier to cover the back, but this ought to have its own shoulder straps since attached packs/bladders are relatively inaccessible, and problematic when riding in vehicles. Even weaving some 1" webbing through the existing PALS loops on the rig will help a bit.
As you surmised, painting the vest can be problematic, as the paint will wear off of the high spots eventually.
Exactly what color/camo you use is up to you and the environment in which the PC is most likely to be used.