I don't know about hogs... but, I KNOW that deer do NOT see orange. (Time for a story... just for TLM)
In '08, I was out elk hunting, south of Mt. St. Helens (in WA). As is with my luck... deer season was closed, elk only. So... there I am, sittin' on a stump, leaned up against a tree and less than 100' from a logging road. Had my hand in my coat pocket and was just sittin' there enjoying the smell of the forest. This part of the forest isn't OLD growth, but, 2nd growth timber country. Just high enough that the underbrush isn't quite as thick as it is down at lower elevations.
04 does round the bend and head straight towards where I am... then pause on the road in front of me and pose. 100% relaxed. After a few minutes of watching 'em pose, I gave a squeeze on my cow elk call (inside my pocket). Since I hadn't (visibly) moved, all they got was a sound from the silence of the forest. All four noses pointed right at me and they just stared, searching for the elk. Unable to locate the source, they went back into "pose mode" (short attention span, I guess). Well... this is fun, how often does a guy get to torment deer on their turf? So... I give 'em another bleat. Again... all noses pointed at the tree I'm leaned against, but since I'm not moving, they couldn't pick me out. I was in full camo, and wearing an orange camo vest.
After about 10 minutes, they decided the runway show wasn't paying good enough and started down off the road... just to my left. They all walked within 20yds of me, but, couldn't find me when I was givin' them a parting bleat. And, they wandered off, never knowing how close to death each one of them was. About 20 mins. later... another four does/fawns appeared from another direction, and, got the same torment from me the first batch had. They too... never made me... sitting in the open, leaned against a tree, "still".
Nope, never saw an elk that outing... saw some more deer though.