The sandwich cutouts give the deep blue dial familiar Panerai depth. Against a ceramic case, those broad markers keep the center readable rather than letting it dissolve into one blue field. Titanium introduces a cooler counterpoint, and the Luna Rossa rubber-textile strap keeps the watch casual. Leather would shift the mood away from the racing treatment.
The blue case also changes the way the substantial QuarantaQuattro wears visually. Where polished steel reflects the room around it, the matte ceramic keeps the color more constant. The titanium elements temper that coverage, and the sandwich markers keep the dial from becoming a flat extension of the bezel. It is an assertive watch, but not a random collection of blue parts. The materials have distinct jobs within one closely controlled palette. The bezel's luminous pip adds a useful point of orientation without interrupting that broad blue outline.