There isn’t that much literature on technical examination of Amedeo Modigliani’s paintings. Last year I worked on a drawing attributed to Modigliani and I could find few references.
The most important study is the one accomplished in the occasion of a rare Modigliani exhibition held in Paris in 1981 . It compares Multispectral images of the paintings gathered for the exhibition (X-radiographs, Infrared reflectograms, UV fluorescence and raking light images) and reports on the X-ray fluorescence analysis of the pigments. Remarkable is the documentation and comparison of a number of Modigliani’s sign in those paintings.
A case of forgery discovered by scientific examination is illustrated by . The identification of Schweinfurter green and cerulean blue didn’t match with the known palette used by Modigliani.
By the way, the same paper cites the existance of a database of pigments used by Modigliani, owned by the Laboratoire de Rechereche des Musees de France. Though, I could not get any further information on this database.
 G. Garnier; D. Marchesseau “Amedeo Modigliani, 1884–1920 exposition 26 mars-28 juin 1981”, Musée d’art moderne de la ville de Paris.
 R. Klockenkamper, A. von Bohlen and L. Moens “Analysis of Pigments and Inks on Oil Paintings and Historical Manuscripts Using Total Reﬂection X-Ray Fluorescence Spectrometry” X-Ray Spectrometry 29, 119–129 (2000).