Error coin - unusual color.

This 1971 Lincoln cent has been graded by ANACS MS62 and it has an unusual color. Unlike the normal bright "reddish" copper color, this one exhibits a bright  brass color.

The Coin was sent to ANACS for verification but they would not confirm what is the material of the coin. It was graded as MS62

Take a look at the picture and you will notice that it has the unusual brass color

Attached is a copy of the slip from Anacs