Lightning Blast Scaling

I know there’s a node “Supercharged Floes” in the Lightning Blast skill tree that converts the damage to cold. However, I did not pick this node and yet hovering over the skill shows “cold” and not “lightning” as a scaling tag. Which damage type scales this skill?

Lightning Blast is a Lightning skill that scales with Lightning damage.

There is another way to convert Lightning Blast to Cold damage, it’s a passive node in the Mage mastery tree. If your Lightning Blast says it’s Cold, and you do not have any points in Supercharged Floes, it means you have that passive from Mage mastery tree.

Thank you. It is Rune of Winter passive in the general mage tree.