"dont need to download them over and over again."
If you want me to explain to me why you do NOT need to download over and over again,message me, no need to spam this post even more.
Server texture packs need to be downloaded every time you join a game that requires said texture pack. When you download it, it does store inside a folder in your .minecraft. However, once you leave the game to the arcade, the server doesn't need you to use the texture pack, so you go back to using your texture pack that you were using, causing a major lag spike which lasts about 5-10 seconds, which is something you have to go through every time you leave and join paintball (since paintball isn't a lengthy game, you must go through this process many times). So, if you join and leave, the texture pack will indeed "uninstall" (but the texture pack is still in your .minecraft, which makes the rest of the installations much faster). One way to fix this issue is to make an arcade texture pack, so that when you join paintball you already have the texture pack required in use, and when you leave the arcade you don't need to uninstall the texture pack again, just like Lucky Islands.
Back on topic:
This does seem like something very unique, but the whole process of making it happen isn't worth it to just have 5+ colored snowballs.