Not that this would help you, but I conducted some experiments a few years back. Unfortunately, I can’t find the pictures because my device ran out of cloud space……. I read as much as I could and watched YT videos.…many sites were actually either sites for making lifelike reptile enclosures, or sites for making props for plays, etc. The problem is in finding a “finish” that will be weatherproof. I never completed the experiment, but I did learn that DISTRESSING the PVC pipe as much as possible went a long way in creating a more natural look, and helped the finish adhere better. We’re talking Dremels, lots of sanding, and creating gouges, etc. There are PVC dyes or stains (I think they are dyes, rather than paints) that you can use. Again, it’s been a few years so I don’t recall specifics.
My inspiration was to have a border of vertical PVC pieces, side-by-side, pounded into the ground…..to simulate bamboo border about 10” tall. As far as I ever got was to distress several pieces of different diameters of PVC and “stain” them with purple PVC primer. They really looked good and lasted, well, forever…..but they were purple. It was just an experiment, but it worked amazingly well.
If the PVC pipe was sanded enough, maybe even Krylon would work. Using a rubbing technique, or even lightly spraying with a few different colors, you could achieve some depth and a look or realism. I made a trellis for our mailbox once, and spray painted it to look like old iron pipes using about 3 different paint colors. It eventually fell apart because I didn’t “glue” the pieces together, but the paint job held up.