Hero's Head Gear +1

So I was buying my heros their runes and noticed that the headgear bonuses are all "item's attribute +1". Now I assumed that "items attribute" was in reference to the attribute of the hero's weapon. However if you remove the weapon from the hero the attribute remains the same, and when the weapon is equipped the attribute count is not blue. Was my assumption that "item's attribute +1" was in reference to the weapons wrong? If so what is it pertaining to?

It's pertaining to the Rune placed on it.

So if you place a Superior Rune of Axe Mastery on Koss, it'll produce a +1 value.

Thanks. Odd that it should be worded that way..."item" rather then "attribute".