RESEARCH:
Blue Amberol cylinders have plaster cores and their titles are printed on the end. All Edison Blue Amberol cylinders have Thomas Edison's signature on them and a special code after the "PAT'D" mark. This particular cylinder is Number 3408 - Waltz Memories, performed by the Jaudas Society Orchestra and recorded on November 7, 1917. If you look closely, you can see the code ".24". This means that this particular cylinder is from Master Recording (Take) 1, and it was produced on Mold Number 24. Similarly, if a record is marked "...78", then it is from Mold 78, Take 3. Some collectors prize lower mold numbers, because they supposedly sound better. Apparently, a limited number of molds could be made from a master take before it began to wear out.
Popular Series Blue Amberol cylinders range in color from powder blue to black. Most are dark navy blue. The powder blue color resulted from an ill-fated attempt to change the recipe for the dye used to color the celluloid. Supposedly, these light color cylinders were found to be less durable, but Edison chose to trickle them out to customers anyway.  Dealers were told to quietly exchange the records for new ones if the customers complained!  The two cylinders on the right are earlier flat ended records.  After about 1915, cylinders mostly had beveled ends like the three on the left.
1917

Edison cut Popular Series Blue Amberol record production costs by introducing new, cheaper boxes with orange and blue graphics.

1918

Edison introduced the "Royal Purple" series of records to replace the Concert Series.  The celluloid plastic record material was dyed purple to distinguish the Royal Purple records from the Popular Series.

1921

Edison Royal Purple records were discontinued.  This left only the Popular Series of cylinder records in the product line.