I participated in the Second Philatelic Summit (4) Sweden Error of Color Stamp Yellow Skililing Banco

I found the Sweden Philatelic Society welcomed the philatelists who came from all over the world with the fact they gave us one black book as a present. The Chairperson herself came to the summit.


It said Den Gula Treskillingen. Den is The, Gula is Yellow, Tre is three and you know the currency of Sweden when they started issueing stamps was Skillingbanco.
So you can find which stamp this book is telling.


Well , this  error of color stamp!
The regular color is green as I show you the image of Stampedia Sweden Stamp Catalogue below.
There are still some philatelists who are still suspicious for its genuine of this stamp, however it is the most expensive single stamp in the world and the owner paid for it  2,870,000 CHF when he/her got it recently. I'd also tell there are many some covers and multiples much higher than this stamp in the philatelic world.