Here are two copies of L. Frank Baum's American Fairy Tales, published in 1901. I've had the copy on the right (with red flowers on the spine) for some time, but I just picked up the copy on the left with dark green flowers.
Both copies are worn, but this is a title that often seems to suffer from excessive wear. In fact, I've seen more copies on which the cover has nearly been completely obliterated than otherwise! I'm not sure why this should be the case - obviously white cloth tends to muck up faster than other colors, but I shouldn't think that would make the inks more vulnerable. Perhaps it's just an anomaly of the copies I've personally run across.
The green flowers seem to be less common than the red, and it's interesting to note that the copy with green flowers uses a brighter tone of red for the cover image than that seen on the version with red flowers. Also, in this case, the stamping has left a sharper impression in the cloth on the green flower example. It's all minor details, but for me that's a large part of the fun and interest of collecting!