I've backed off of vaping CBD for the most part. I mixed my own from 99% (whatever) isolate. Mild heat and full VG. When mixed, it is in essence a suspension. One can observe not 'particles' but rather slight light distortions in the liquid, but no separation or color. After a while sitting in a bottle I began to notice some collection of material on the inside of my bottle above the liquid line. It may have had a very slight blush color. In reading I found that the base constituency of CBD is not water soluble, but more along the lines of an oil. I had known that, but ignored it until I found material collecting on that inside of the bottle (poly). Since I really wasn't needing it, I decided to set it aside, though take a few puffs every once in a while. Your knowledge, understanding and experience may vary. PS I just checked the 60ml bottle I had deposited the contents in maybe 8 weeks ago. I'm seeing the beginnings of the material collecting near (below) the liquid level. Similar coloration as before.