Nice photos.
I have been mixing my own lately. Start with yellow and add a drop or two of black for Yellow ZC. Add more black for Green ZC. Not sure why I mix my own. Think it started when Pollyscale went out of business–I had lots of their yellow and black paint, but not much interior gree–plus they did not make yellow ZC that I know of… I think mixing your own can also make the hobby more fun… at least for me…
Mixing your own also lets you get a semi gloss or gloss version of a color that usually comes pre-mixed in flat.