In 1847 the authorities of Mauritius, then possessed British, willing to equip themselves with their first stamps, won the primacy of the first clamorous press error, emitting a series entirely similar to Penny Black but on orange/red background (1 penny) or indigo (2 pence) and with the erroneous words of "Post Office" instead of "Post Paid", ie of "Post Office".
These are now among the rarest stamps in the world, as they were immediately withdrawn: 14 (of which 2 are new) remain for One Penny and 12 (of which 6 are new) for the Two Pence.
On July 1, 1855, Sweden issued its first stamp of the value of 3 skilling, committed the first non-compliance between a decree of issue (which had foreseen it green) and actual print (which was in yellow), thus giving history one of the rarest stamps in the world, the yellow Treskilling, of which there is currently only one specimen.
The most famous mistake in Italy concerns the 205 lire pink lira (called for this pink Gronchi), issued for the occasion of the visit to Peru of the President of the Republic Giovanni Gronchi, which reports the borders of Peru in a wrong way and that for this reason it was withdrawn from the trade a few days after the sale, being replaced by the common "Gronchi gray".
The Pink Gronchi is the most famous stamp of all emissions of the Italian Republic, but not the most quoted; often of it were produced various fake specimens sold to collectors.