A film has been placed over the crystal to give each bear their color. There is also red, black, and silver. In their original boxes a black foam was used to fit the bears snugly. The foam adhered to small areas on the film over the bears over time and looks like a light fingerprint, or very light smudge mark.
Most are barely noticeable and on the back or arm of the bears. If you zoom on the back you can see two small areas, each less than the size of a dime, where there are the light marks.
These would not be noticeable if hung on a tree. Gift - Comes with a Gucci Bear Tag which can be placed on a key ring.