According to Mr Google, the "Bandiera" livery was introduced as of 1972 for domestic "TEE" services:
TEE Cycnus (Milano-Ventimiglia)
TEE Adriatico (Milano-Rimini-Bari)
TEE Vesuvio (Milano-Napoli)
In 1974, they added two more trains:
TEE Ambrosiano (Milano-Roma) and TEE Aurora (Rome-Reggio Calabria). The second lasted only one year before being converted to a night train.
The rolling stock for these domestic TEE trains was added to orders for the red/beige TEE stock, but was delivered in the new Bandiera livery with the red stripe.
After the end of international TEE services, most of those trains were converted to IC. The domestic TEE trains followed in 1982.
The major international runs saw the first introduction of the new Eurofima coaches as of 1977. The advantage was that the new coaches did not require the generator car that the TEE/Gran Comfort coaches required. As the FS had only a limited number of the new coaches, some consists continued to include the TEE coaches. Once second class was added and the trains were relabelled as InterCity trains, the FS deployed the new Eurofima second class coaches in those trains.
At the same time, in view of the domestic TEE trains also switching to InterCity trains, the FS ordered a series of new second class coaches, which were based on the design of the Eurofima coaches, including air conditioning and the compartment design. The new coaches were delivered in the Bandiera livery, but had a blue stripe instead of the red stripe used on the Gran Comfort stripe.
I would like to know if the TEE coaches still required the generator car or whether they were modified or simply did not require it for domestic traffic.
The GC coaches were always numbered 50 83, so they were never authorized for international traffic. The second class coaches of the Next Generation of the Eurofima type were numbered 51/61 83 and were equipped for international traffic. As the FS required additional coaches for international trains as new routes were added, the Bandiera coaches started to appear in consists, but the top tier trains were entirely made up of the C1 (Orange) Eurofima rolling stock. In Switzerland, most of the trains running FS stock was either made up of the C1 Eurofima material or by UIC-X and older types in the Rosso-Fegato livery (Red/grey).
In the 90s, the Top tier rolling stock was to be painted in the new Bigrigio livery, but it was not too long before the decision was taken to adopt the new XMPR livery, so by the end of the 90s, it was common to see trains operating with a mix of C1, Bigrigio and Bandiera liveried coaches. Most often, the coaches in C1 were the first class Az. The second class coaches were commonly in the Bigrigio and Bandiera liveries.
The next time I saw such trains (2003), it was a mix of XMPR, Bigrigio, Bandiera and C1. By Winter 2004, most of the coaches were in the XMPR IC/InterCityPlus colors and then in 2005 by the new Cisalpino livery.