Make item attribute modifier look normal

Hi guys, I'd like to change the attribute modifiers of a sword. I already tried managing with attribute_modifiers component and it seems to be working, but two things are unclear to me: 1) Do values get added to the item default ones, or just overridden? 2) Why are modifiers showing blue in tooltips, and not green like item default ones? How to change this to make the modifiers look standard-like?