The main constituent parts are the forged carbon case and the ceramic bezel, not the buckle, the caseback, nor the strap plots attaching it to the case; although, if you go by Audemar’s model designation, 15706AU, they effectively referenced the white gold hour markers and hands.
Conversely, with the 15707CE, they nailed the fact that both the case and bezel were ceramic, yet with the same bits of titanium and white gold as the FC.
Logical thinking obviously wasn’t someone’s strongest attribute!