The indoor Access Point line all have vent holes. The vents help with heat dissaption, and don't normally have any negative impact on teh operation on the access point. HOwever filling these vents with paint likely isn't a good idea.
The enclosure is the best approach, not only to address your asthetics goals, BUT ALSO at the same time addressing PHY security concerns that will creap up later when devices start 'walking away' from the landscape.