I live at 8,000 ft. elevation, 90 miles West of the Tonopah (NV) beacon in Northern California. West bound traffic vectors off this beacon then fans out to different destinations on the West Coast. Subsequently, i get a lot of traffic overhead and I have daily occurrences of fresh trails, chembows and other phenomenon in my sky.
In the last year I have noticed two or three new phenomenon in the sky.
Specifically, I have noted that:
1. Two simultaneous trails being created by different aircraft at the same altitude produce trails of different colors. One trail may appear white, while the second appears slightly blue tinged.
2. One aircraft may produce a normal contrail while another produces an aerosol trail.
3. Most significantly, I have now observed that most ambient clouds, especially cumulus clouds, exhibit oil slick coloration on their edges when viewed in certain lignt. In this photo, note the chemical colors at the borders of the center cloud, just above the treeline. This cloud was at approx. 9,000 ft. in elevation.

This recent development suggests that our atmosphere is now completely saturated with these chemicals. The potential ramifications of this fact raise legitimate concerns as to the "weaponization" of our atmosphere.