Here is the idea;

Basically changing the size of the dice makes a difference for offense or defense.

The most sides the dice has, the more it benefits attacker advantage (the odds of a tie getting lower which are in benefit of the defender) and vice versa.

(note that for each bonus/normal/malus both attacker and defender use the same type of dice; 8vs8 sided dice, 6vs6 sided dice, 5vs5 sided dice):

red trade: this is bad news for you, if you trade this you will roll 5 sided dice for your offense/your opponent's defense, on the consecutive turn your opponent will roll normal 6 sided dice, so will you.

green trade: you have normal 6 sided offense dice, on the consecutive turn your opponent will roll with a malus of 5 sided dice, so will you.

blue trade: you get to roll 8 sided dice for offense , on the consecutive turn your opponent will roll normal 6 sided dice, so will you.

rainbow trade: 8 sided dice for offense, on the consecutive turn your opponent will roll with a malus of 5 sided dice, so will you.

trading a territory spoil gives that territory the 1 round rainbow trade power no matter the colour of your trade.

this would be a new option for spoils other than escalating, flat rate and nuclear and would award a new type of medal.