Purple hue vs clear

https://nchfp.uga.edu/how/pickle/vegetable-pickles/kosher-style-dill-green-tomato-pickles/

Using the above recipe, I pickled two different varieties of green tomatoes. I halved the recipe because of the quantity I had and it resulted in 3 quarts. After processing, two of my jars had this beautiful purple hue like the one on the left. The one on the right is more clear.

The one on the right also had some salt on the rim after processing, I wiped off some of it, but you can still see some of it on the side of the room there in the second photo.

My hypothesis is that there are just more of the variety “midnight snack “ tomatoes in the purple ones because those tomatoes are black with green (red and black when ripe ) and I think the pigment it creates is kind of purple. But I don’t want to assume which is why I am asking here. Perhaps I should not mix varieties of tomato like this when I do canning, but my understanding is that they were interchangeable and I like the variety aesthetically.