Modern Seagrams V.O. Plum Purple 1 Gallon Whiskey Bottle

This caught my eye sitting on a table of dumpster fill at a yard sale because it just looked different than the standard jumbo whiskey bottles I've seen. It is not the usual dark amber or brown glass for this product. It's a distinct reddish plum purple color. Anyone know if this was a normal color for these or is it possibly a glass mixture production fluke. It's an Owens company US made bottle with a date code 68 to the right of the trademark logo.