Twelve Days of Christmas, Imperial
Beginning in 1970, Imperial produced a series of plates depicting the the song Twelve Days of Christmas. Each plate has a different stanza and each in a different color. Shown here are the first and last plates in the series; "A Partridge in a Pear Tree" in cobalt and "Twelve Lords A Leaping" in red. On ebay these plates sell for an average of about $20. I've have records of three complete sets selling, one for $128; another for $150; and the third for $214. They are often found on eBay.

Tony DeMichael provides this information about the Imperial Christmas plates:
The first plate was issued in 1970 and the twelfth in 1981. By the way, the first plate was issued in Aurora Jewels (cobalt). Prior to the cobalt, Imperial tried to make the first in 1970 in red. They didn't have much success and only 11-12 were made in red that first year. If you ever find one of those, hang on to it, or call me! As the years progressed, with a different color for each year, the final plate was made in 1981 in red. By that time, Imperial was able to make red with success. Anyway, after the last in the twelve, Imperial embarked on a new series of plates. In 1982 Imperial introduced plate #1 in the series of Christmas Carols. Plate #1 in 1982 was "Hark The Herald Angels Sing" and it was made in blue, a slightly lighter shade than cobalt. Of course, the next year Imperial went out of business and only this plate was to be the only one of the new series to be made. I don't know how many were produced, but we feel lucky to have one.