There is an interesting idea idea elsewhere for a "Nemezis" orange dice.
I think this could be very useful, particularly if it had a chaos star.
I think the 'unreliable' quality is not quite balanced (sorry if I misunderstand the rules):
A blackpowder weapon blows up in your face when you roll a number of chaos stars equal to the unreliable rating of the weapon.
The weapons in the rulebook have either 'unreliable 1' or 'unreliable 2'
This means that you have an 'unreliable 2' weapon and stick to only using it in situation that has one challenge dice, most ranged weapon actions, you are safe from misfires!
It also means that an 'unreliable 1' weapon is going to blow up 1 time in 8 on average! Ouch!
Having an orange dice with a chaos star could be used to tone down the chances of a misfire; the orange dice has to be the chaos star for the weapon to explode (1 time in 12 now); and an 'unreliable 2' weapon now can misfire, though it is very unlikely.