I don't think that's completely true, you watched the extended version, right? From what I understand, it wasn't bringing it up to the same level as the others so much as adding a single, constant tint throughout the entire film, on top of the pre existing color correction. I thought I heard speculation somewhere that perhaps it was a technical error because it would be such a bizarre choice to make. I certainly hope it won't be in the hobbit, though luckily I don't think its very likely.