How do you know that?

I've put at least 150 hours into the game and on epic modifiers harpies, shanks, and psions get shield so far queens's wrath (over) + nightfall

you tell the shield weakness by the color around the shield solar=red arc=blue void=purple

Right, right. When I asked that question however long ago that was, I hadn't yet realized that Wizards always have red shields, Captains have blue, Minotaurs have Void, etc. I thought that the shield colors could be random then. I know better now. Thanks though.