Orange separates more obviously and more quickly than Mandarin. A clear 10ml vial of Orange will separate into 2 distinct layers. The top is very near colorless and clear as water. The bottom (say 5% of the height of the bottle) is opaque, white-ish. When you shake it, it looks sort of foggy. You can still read text through the bottle then, but it's....foggy! Like you put a couple drops of milk in 10ml of water. If you shake it, then let it sit, you can see it settling after no more than 30 minutes, MUCH faster if it's cold.
My Mandarin has been untouched for weeks. I see no separation. It's ever so slightly pale yellow and less foggy than Orange.
I know both separate into layers, whether you can see them distinctly or not. Many flavors do, from all manufacturers. I figured it out the hard way, by not shaking before measuring out (using a syringe near the top of the vial. I thought I had "bad bottles" until I realized (duh) I should shake 'em before use. I'm a dedicated shaker now, no matter what flavor/juice I'm dealing with!
I doubt I've ever used over 5% of either FA Orange or Mandarin; at those percents, neither produces foggy "squirt" looking juice.
By the way, cold temps can cause some flavors to look foggy, even if they're clear at warmer temperatures. I see it with many of my flavorings, because they "live" in a fairly cool spot.
