If I can believe this article (http://nerdist.com/behind-the-costumes-outlander/), the show is attempting to be as authentic with the tartans as possible, to what they would be wearing in 1743, with the dyes available to them at the time, so much more muted variants of the modern ones.

There are three hunting tartans on Clan Fraser's website. None of them are remotely like the one Torrid is using, which is simplified.