I’d love the ability to change the color of the jetpack trail/smoke separate to the actual jetpack model. That way I can have, for example, the diamond jetpack with a pink trail, or the new invisible jetpack with a different color sparkle, or the rocket jetpacks with a different smoke color.
There are various ways to go about this though, considering jetpacks already have their own colors:
-Jetpacks could come with a default color, yet be able to be changed once right-clicked, diamond jetpack having the ability to choose multiple colors (due to rainbow design)
-Have colors be completely separate to jetpacks, being able to choose 'em and buy 'em on the appearance tab, jetpacks could come with unlocked colors (Eg. rainbow color can only be unlocked once you got the diamond jetpack, or perhaps better yet the ability to choose multiple colors could be unlocked by getting the diamond jetpack, so you can customize your “rainbow”)
I love my diamond jetpack but wish I could change the rainbow colors to fit my “aesthetic” vibe (To something like Pink, Purple, Cyan and Blue)
Unlocking new jetpack trails could also be some really good plaza milestone rewards, or something you save up for to be able to better customize your character!