I agree they are different 'shades.' I was the one suggesting that.
Parcelpostguy made a valid statement
As to color differences, if any, do allow for the fact more can effect a used stamp than a mint stamp. Used stamps get soaked, some times a lot and repeatedly over many decades. I would say the unused was printed before the used.
You should take care 'identifying' those 'shades' from used stamps as colours are affected by soaking. Some of these reds are known to be very visible from the back of the stamp. Without going into the discussion about 'scarlet', 'deep scarlet', 'carmine', etc. it is that difference in the visibility of 'a red colour' that is indicative of two printings.
One likely being carmine and the other scarlet might also evidence two printings. Being able to see it from the back tends to avoid that issue with the Victoria Jubilees and Edward VIIs.
It is a nice find. It is no 'plate damage' or 'broken frame' variety. And I doubt it is a foreign object on the plate that caused it. I think a fold -probably more a wrinkle as the stamp is not wider at one and than at the other - is a good candidate. But it is not a major pre-printing paper fold.
Certainly a nice addition to any collection.