I have Apples near my Campsite, that make it look good for me since the Campsite is orange but in other way you can make some combinations too, like:
-Apple-Pear.
-Orange-Cherry.
-Maybe normal trees.
Maybe oranges? the campsite is completely orange when somebody is camping out, so I think it would look nice matching with the campsite and with the brown of the trunks. I'm trying to think of what fruit would make the most sense to be in a camp-out area, since it's unlikely you'll find tropical fruits near one but durians could work too. Just anything with orange or yellow tones really and you're all set.
My campsite has a blend of Cedar Trees, Lemon Trees, and Holly Bushes. Yellow Pansies scattered around it as well, but I wish Dandelions were more stable - then I'd use them instead.