Olive colored Queen Victoria s Head
Printed in 1864, this is the most expensive historical postage stamp of Hong Kong. However, due to a printing error, 52 sheets of the stamp were printed in olive color. The stamp's watermark was wrongly styled, and the word "CC" was printed in the wrong place. Among all 40 pieces of the Olive-colored stamps there is only one block of four such stamps existing.
Estimated Price : $824,648