This is a pretty good topic. I know that if the animals are desensitized to any sort of vehicle (tractor, motorcycle, ATV, truck) they'll let you get closer than something their not used to. Several years ago when I was just a pup, I went antelope hunting with a friends dad out in the prairie where he ranged cattle on the blm ground and was out there checking on wells and stock a couple times a week. We started to notice that the goats would let you drive within 150 yds or so and stop and glass, but if they saw a door open they'd bolt. Same thing if you turned the engine off.
Since then, I've been experimenting with some different tactics to not spook the animals as in to just continue to drive by them while they can see you and going over a ridge before stopping to get out for example. I think that the thing with a white pickup is a matter of the truck probably stuck out like a sore thumb on the prairie.
For the guys that are going to convince the wife on the logic of getting a new truck because antelope are too spooky around the current vehicle, I'd definitely go with a forest green color instead of blue as it's much easier to convert to some sort of camouflage.
