For more than a half century Rolex aficionados associated Rolex GMT-Master with two bezel color combinations,with their respectively nicknames: "Pepsi" for red/blue or "Coke" red/black. When another GMT bezel version was presented in black/blue, the aficionados called this one "Bruiser" and "Batman" .
Rolex succeed in combining two colors of ceramic in a single piece insert (Patented by Rolex). This special ceramic technique had never been previously achieved. The first GMT bezels were made of metal (Non-Ceramic) and came with Oyster watchbands. In 2005 Rolex began to shift to ceramic bezels with just one single color.
The advantages of ceramic over metal, are better scratch-resistant and being less likely to fade after years of exposure to light. For the next two consecutive years, Rolex brought out steel, two-tone, and all steel versions of the GMT Master II, both with all black ceramic bezels and Oyster watchbands.
Rolex new combination colors on their bezels are more practical and easier to read of the wearer. In a GMT watch, a bi-color bezel makes it easy to distinguish the second time zone's A.M. hours from its P.M. hours. In addition, they make the watch more attractive and appealing to the eye.
