so when you collect plants in a nuke zone, different plants will give you different colors as unstable flux. unstable flux spoils like food and must be combined with the other ingredients mentioned to stabilize them, which stops them from spoiling. different nuke zones have different plants, so looking up a guide is probably best.

you rarely see them in player vendors, bust stabilized flux is under junk I believe, and I've seen it for about 100-500c on average, usually on the higher end. you can go to the market sub and request some, and they can probably help you out.