Colour coding for different warheads, definitely. We want the player to be able to see exactly which kind of warhead is which without referring to text.
So far we've got three types of rounds planned:
High Explosive -- Orange and black pattern.
InCendiary -- Red and black pattern.
Antimatter Explosive -- Purple and orange pattern.
Big stripe of the primary colour, small stripe of the secondary colour, big stripe, small stripe, big stripe. Any lettering is up to you.
As for the shape, it depends on whether we're making this a rifle or a smoothbore recoilless gun. In this case I think it would make more sense as a smoothbore, because militaries in this setting wouldn't be using much unguided ordnance before the invasion and you need fins for guidance. I also like the idea of this relatively new gun loaded with antiquated ordnance.
So, would you be able to create a non-rifled recoilless shell with retracting fins? Control surfaces on the fins aren't necessary depending on the backstory.
Regards,
Winter