I think Siggy and Floki have a heavy make up... they're really black around their eyes! Did the vikings really use make up?

Only ocassionally: Floki sometimes: I know it is to enhance & make his character stand out more, and definately do not care for some of the exageration of the "Wise/Ancient One" - because i don't get it, I think that was just for dramatized interest. Otherwise-No, they are minimal & fine, and natural. The Blood & dirt sometimes looks a bit studio, but subtle enough I'm sure to most, and the make up used for battle using surrounding elements is accurate enough for those times -like war paint, and many cultures did this in prepartions. So it's cool. :)

Floki, Siggy, and the Seer are the only ones I can think of who really wear make-up. Siggy's makes sense. She's very ostentatious with the way she dresses, so her make-up would be much the same.
Floki is interesting. He's the only person who we've seen put on make-up, and he seems to be the only man who wears it.

I do think the Seer's make-up is a bit much though.

ETA: Okay, I just rewatched the epis, and Helga wears a lot of eye liner too. BUT she IS married to Floki, so that's another one of those "makes sense" things.

Only few characters really wear much make up. I get why it's needed, so I don't think they use more than they need too.