Here is also a list of Errors in Braveheart, but the painted blue faces are not entirely inaccurate, it's just it was not used for battle and out of practice by the time of Wallace, as the idea of it may stem Pict Tradition.
Error #4: The Scots didn’t paint their faces for battle
At least they no longer did by the time of Wallace. What Gibson was
obviously alluding to is the Scottish Picts’ tradition of painting
their faces blue to scare off those pansies, the Romans, from their
lands. Of course, Emperor Adrian would have nothing of it and built a
wall to keep those evil buggers from sacking the rest of Britain while
the sandal-folk still ruled the scene.
The blue face-paint is so iconic, though, you couldn’t imagine
BraveHeart without it. These days of course the tradition is to paint
the flag of Scotland (a white X across with blue sides) for sporting
Q: Why do they wear blue or blue and white makeup?
If you didn’t know, these are the Scottish colors. You can see them on
Q: What is that paint?
It’s called woad. It’s a plant and the blue dye is produced from the
Q: Did Braveheart really wear that paint into battle?
Probably not. Most historians think the paint was an earlier
phenomenon (Wikipedia has a lengthy section on historical inaccuracies
in the film). We also like the nit-picking produced on this blog’s
History of Picts