This is the point I was trying to make or at least point out the flaw in the grading system. The book I'm talking about is a 1.5. But imagine if it were a PLOD 6.0. The difference in value between blue and purple would be roughly $30k. If you have no intention of selling, then it's a moot point. But if you are planning to sell, it's a grey area that gets more grey depending on the value of the book.
The irony of the whole thing is that someone trimmed this cover in the first place, to increase it's perceived value (pre CGC). The color touch on countless purple labels, the amateur trimming, was often done BY dealers, who now clutch their pearls at the thought of undoing what a generation of dealers knowingly participated in.
P.S. I was only home for one day, so I didn't have time to scan the book. But I'm home on Saturday and will grab it and post, so this morality play can enter it's closing act.