The 1855 Treskilling Yellow is a color error of one of the very first stamps issued in Sweden. The three-skilling stamp was usually printed in a blue green, but an unknown printing error led to a batch of yellow stamps briefly being circulated in the 1850s. Only one Treskilling Yellow is known to have survived, though these stamps were printed in sheets of one hundred, leaving many to speculate that there are more waiting to be found. In 2010, Baron Jean-Claude Pierre Ferdinand Gunther Andre and his wife claimed to have stored nine separate Treskilling Yellow stamps in a trunk inside a Clydesdale Bank vault in London. The vault was allegedly broken into and the stamps were stolen, leading the powerful couple to file a lawsuit against the bank. Both philatelists and the court found the claim to be unfounded, but there are some holding on to hope that there’s a Treskilling Yellow stamp fortune hidden somewhere in the world.