I don't understand one thing, can someone explain it for me?

Unstable Scepter No longer rolls Legendary-strength bonus to Arcane Orb damage as an inherent affix. The damage of Arcane Orb is increased by 350-450% and its explosion triggers an additional time.. Note: Existing versions of this item will also be changed to include the damage roll in the orange text, but will always roll a damage roll equal to the previous maximum possible.

So I have "old" scepter and dmg in the orange txt says 65%, if it rolls new value, how can I know how much I rolled?