Three books printed on blue paper in the 16th C are described in Robin Halwas: Catalogue 5 (a few years back): item 16 (Venice 1548), 106 (Venice 1541) and 142 (Venice 1524). Some 36 books printed on blue paper in the same era, and known copies of these, are listed as footnotes to the description of item 16 (Bembo: Delle rime), which is a short essay on the practice of printing on blue paper in the 16th C, with some references.
I've read that in the 18th and early 19th C low quality paper was sometimes coloured blue: better that than greyish ...
Lorenz B Hatt