6 cent air mail brown?

[pdv006]

Good evening everyone, I just finishing looking thru a envelope of 6 cent air mail stamp and found two brown ones...... am i crazy(yes i have been tested and i am) but i this rare? The top is the orange and the two look brown. Any help is great.

[khj]

The orange turns into black with time due to exposure to sulfur-containing pollutants (such as cigar/cigarette smoke). Sometimes during the transition, it appears orange brown, but is typically very uneven.

This type of oddity is called a color changeling, and usually decreases the value of the stamp considerably. But they are great conversation piece. One of the postage lots I purchased the previous week actually contains several color changelings. Maybe I should start a thread and post pics of them before I use them up for postage!