SWEDEN.1855. 3 SKILLING YELLOW. REPRO.  This stamp was printed in error, the normal 3 Skilling stamp was printed in green, but due to an unknown error one sheet was printed in yellow. The only known copy in existence of the 'TRESKILLING YELLOW' was discovered in1886. This one stamp has been sold a number of times and each successive sale made world record prices for a postage stamp. It was last sold in 2010 for an undisclosed price. Value estimate in 2021 is US$2000000.00 plus. This stamp comes with a 3 Skilling green normal for comparison.