Are amber or olive green jars worth more and why?

Yes, jars in amber, cornflower blue, olive green, etc. are worth more because fewer of them were made and they are in great demand by collectors. The amber jars were made that way as an attempt to keep fruit from turning brown. The amber glass kept out the harmful effect of light rays on the contents of the jar. However, the jars were less popular with homemakers because the contents were more difficult to see. Some jars were made in a dark green color to make contents like olives, for instance, more attractive to buyers. However, most olive green jars were made from batches of jars (often at the end of a day) that had impurities in itself. Consequently, these jars were fewer in number and due to their "imperfection" frequently discarded. In the case of the Kerr Self-Sealing masons found in cornflower blue, the company was trying to make green jars for a customer but the glass kept coming out in the wrong color. These off color jars are easy to spot by anyone who has seen a few jars ...  more