Yes, you are blue.

That is, in fact, completely untrue. The people of the Scottish Highlands, first known as the Picts and later as the Scots, did indeed use blue coloring before battle. Before about the year 1000 CE, the Scots used to bathe in the blue pigment before battle, so that all of their skin held the blue tint. It was believed to strike fear into the enemies. Later, even until the later Renaissance period in Britain, and well after the Act of Union which made England and Scotland "united" into one kingdom, the Scots still used the blue pigment when meeting their enemies. In the later dates, however, they used it as a paste and slathered it across their arms and face, both to strike fear into their enemies and to taunt the English. There was a law passed in the area of Inverness well after the Act of Union that actually outlawed the use of the blue pigment, proving that it was indeed used by Scots at the time of William Wallace, and after his death.

No, you're not.

Contrary to the assertions in comment no. 37377, it is true that in the 13th century Scots did not paint their faces blue, when going into battle or otherwise. To the best of my knowledge, the last contemporary or near contemporary reference to anyone in what is now Scotland painting or dying their body dates to circa 600, from Isadore of Seville in his 'Origines', who says the Picts got their name due to the tattoos they had [ref. Laing _The Picts and the Scots_, 1993, among others]. One can argue over whether to believe Isadore, but even if one takes this at face value, that is tattoos of unspecified color (permanent), not woad or blue paint before battle (temporary), some seven centuries before William Wallace. I have yet to encounter any contemporary description of later Scots (the Picts disappear from record by the 10th century or so) painting, dying, or tattooing their bodies or faces blue or any other color for any purpose -- well, until the advent of late 20th century football/soccer fans, that is! And while I am perfectly willing to believe that in the 18th or 19th century there was a statue passed in the Inverness area regulating blue dye in some way, I expect the dye in question was used on cloth and the like, not people. If there is specific evidence to the contrary, I would love to know of it -- a citation of a reliable source that quotes it should do.

History

Once again, I do not believe you can use history as a reason to nitpick the movie. We, in fact, do not know that this ritual was not used at this time. That cannot be proven. Furthermore, a nitpick is only valid when it is in relation to the movie itself. The film does not claim to be historically accurate. History cannot be used to nitpick this movie. You must look at the movie by itself. This should be refuted along with all other nitpicks of this nature.

no proof that it WAS done is not proof that it WASN'T done.

This nitpick and accompanying comment seems to be basing the nitpick on the fact that the last known historical reference to the blue paint was well before the movie is set. But while this may be true, there is also no historical evidence to the contrary. Nothing that makes a reference to Scottish clans NOT wearing blue face paint in battle. Therefore, no one can say for sure if the nitpick is right, or the movie is right.

Epistemology

Comment 63039 touches on matters that go far beyond this nitpick. In the absence of direct information, is it possible to make a judgment call on any historical matter? The commenter says "No" and his point seems to carriy some weight. The question is if it carries enough.\r

Without a direct eyewitness statement either way, it is indeed true that both possibilitees remain open: the Scots either did or did not use some form of warpaint. However, we would be wrong to consider it a 50-50 proposition. It is overwhelmingly more probable that they did not. The reason for this is quite simple: the ordinary, common, usual, and standard are hardly ever mentioned in a report. It is the extraordinary and unusual that are mentioned. Here is an extreme example of the principle. We would certainly not expect anyone to report that the Scots did not chop their left ears off before going into battle. They didn't, but it would not be reported because no one did such a thing. Yet if they had, it is inconceivable that nobody would mention it. The point here is that the thing is not  symmetrical. \r

Let's try another. Consider any encyclopedia or other reference work's information on, say, the Pygmies. They will all mention that Pygmies are short, because it is unusual. They will not bother to mention that Pygmies have two eyes, two arms, two legs, no tail or wings, or any other trait universally shared by all human beings.\r

Returning to the question of whether Wallace's forces used warpaint, the principle may be easily applied. If they did decorate themselves, we should expect it to be mentioned; if they didn't, we should expect no mention of the lack. As the accounts say nothing one way or the other, the conclusion must be that they did not wear warpaint. \r

The Past is fixed, but History does change in order to accomodate new information. If some new document were to turn up tomorrow that states that the Scots did  paint themselves, our judgment would have to be reversed. This sort of thing happens from time to time. Absent such a document, logic indicates that they did not do so and that the nitpick is valid. (We are giving credence to the factual claims, regarding dates, of the nitpicker and the first two commenters. The validity of claims of expertise and who to believe are another matter entirely.) For the reasons given, what we should not expect to surface, tomorrow or any other day, is a document stating that the Scots didn't  color themselves.

Chaos

The author of Comment 62963, History, seems to have missed that there is an entire category of nitpicks on this very point: Historical Fact.\r

Let us follow the commenter's dictum that "a nitpick is only valid when it is in relation to the movie itself" to its logical conclusion. What is being applied to History here, might just as well be applied to Science and Technology, eliminating those two categories, and taking Vehicles and Weaponry along with them. In fact, as every movie would be sui generis, living in its own little surrealist universe, Editing and Plot would go too, as, for example, coffee cups would not necessarily be constrained not to move around of their own volition when camera angles changed.

Once one detaches from reality, the descent into chaos has begun.