Occasionally postcard backs (usually real photo)  will appear yellowed, which is a flaw from my scanner. If there is no staining mentioned in the condition statement, the card is not discolored.  Also if odd colored lines appear this is also a scanner defect unless mentioned.  Add me to your Favorite Sellers and feel free to email me with questions about item conditions as I try to describe them accurately.  Please Visit My eBay Store, new items are added every week.