Question about lincoln cents grading

[EgCollector]

The following is written in the lincoln, wheat ears reverse page of the 2008 Red Book;

"Dicoloured (brown) or weakly struck piecesare worth less."

what is meant by the brown colour; is it the colour of the whole coin or he means the brown spots or areas of corrosion that may affect the coin.


Thanks

[Pocketcoins]

Age will make the copper in older cents sometimes take on a brown look, but a lot of collectors want red looking coins. I think I read someplace it's the oil from your hands that makes the copper turn brown but am not sure. Myself I like the brown better.

[EgCollector]

Thanks Pocketcoins