1903 5C PR67 Cameo PCGS. This year marks the first year proof coinage was available after 1901 with any degree of cameo contrast. And the few coins that are available as cameos are not a result of a conscious decision on the part of Mint employees but purely a coincidence of having been struck from a new pair of dies. This is a modestly contrasted example that probably would show a stronger cameo effect but each side is lightly draped in golden and lilac toning.
Proof Liberty Nickel, 1903 5C PR67 Cameo PCGS