When you save your liveries there is two options : "SAVE" and "SAVE AS".
If you change the name and "SAVE", it will overwrite your current livery with the new name.
If you change the name and "SAVE AS", it will create a new livery with the new name, the older one will stay like it was in the previous save.
I need to check but I think if you DON'T change the name and "SAVE AS", it will not duplicate, but still overwrite the previous one. As I can't find an iteration of one of my liveries, I don't remember if it what happened or if I deleted manually.
But you can't rename one of the livery you shared, or once it is applied on a car (You just have to apply the new one and delete the older, in this case).
