It is very possible that the "leather colored" Italians are crossed. But it’s also possible they are just regressing back to their original color before they bred them for color. Brother Adam says in "In Search of the Best Strains of Bees" page 37, 2nd and 3rd Paragraphs:
"There are, according to my findings, three distinct varieties of the Italian bee: the dark leather-colored variety; the bright yellow kind, as usually supplied by the commercial breeders; and a very pail lemon-coloured type, not often seen. The so-called Golden Italian is not a true Italian bee at all. It is an outcome of a cross between the Italian and a black bee, as our cross-breeding experiments have clearly demonstrated.
"Experience has shown that the leather-coloured bee surpasses in economic value the more attractive bright yellow variety. The first queens exported from Italy came from the Ligurian Alps - hence the name Ligurian bee. These original importations, made nearly a 100 years ago, were mainly of the leather-coloured variety, and it was undoubtedly the tawny Ligurian native bee that established the reputation of the Italian. According to my findings, the true leather-coloured bee is found only in the Ligurian Aops, in the moutainous region between La Spezia and Genoa. Immediately west of Genoa, Hybrids make their appearance."