I've been doing some research to keep current on a Business Law course that I am teaching. Apparently blue laws weren't originally written on blue paper as many of us thought they were (at least no credible historical evidence supports this).
Also puzzling to latter-day Americans was the term "blue laws" itself. Why were these regulations called "blue laws"? With no obvious explanation at hand, we invented a satisfying one: these types of laws had originally been printed on blue paper or bound in books with blue covers.
Not so. No one has turned up seventeenth-century sheets of blue paper or blue-bound books containing these laws, nor has anyone found any seventeenth-century references to these regulations as "blue laws." The earliest recorded use of the term didn't appear until well over a century later, when the Reverend Samuel Peters' 1781 book, General History of Connecticut, described onerous colonial laws in the following manner:Blue Laws; i.e. bloody Laws; for they were all sanctified with whipping, cutting off the ears, burning the tongue, and death.
(A variant of this tale posits a self-referential origin for the term by claiming that Peters' book itself was printed on blue paper!)
Although Peters maintained that early colonists did refer to these laws as "blue laws," he did not claim that the name was taken from the paper they were printed on, nor is there any evidence of an earlier usage of the term than his own. Since parts of Peters' book (such as his list of forty-five putative "blue laws") have since been found unreliable, it's possible he may simply have invented the term "blue laws" himself. If not, the term most likely derived from an eighteenth-century usage of the word "blue" as a disparaging reference to something perceived as "rigidly moral" (a "bluenose," for example, is one who advocates a rigorous moral code), not from the color of the material on which the laws themselves were printed.