Here's an idea of easily selecting the desired cannonball for the job using the same familiar menu design used for quests and inventory items.
Whilst holding onto the cannon select your usual key or button used to open the items menu revealing the types of cannonballs you currently have in your inventory and the amount of each type.
Note: this menu will only open whilst holding the cannon.
Like navigating the quests or items menu select either type to change to, otherwise it stays on your last selection until that supply is depleted before reverting back to the common / default cannonball.
An alternative to reverting back to the common / default cannonball, could be that when the selected cursed type is depleted the next cursed type of that colour (side of the dial) is used and so on.
With the exception of regular cannonballs (always at 12 o'clock of the dial), the slots for each type are not permanent, meaning as one type of ball is depleted that side of the dial rotates around leaving the empty slot at the bottom (as pictured below).
Any feedback or modification suggestions are welcome.
