Mark Zuckerberg has never been particularly interested in dressing like a conventional billionaire, which is what made the intensely blue watch on his wrist during his recent appearance on Tiff in Tech so difficult to miss. As he discussed Muse, Meta’s autonomous AI agent, Zuckerberg wore a $225,000 De Bethune DB28xs Kind of Blue Tourbillon, a spectacularly engineered timepiece that looks almost as though it has been dipped in liquid cobalt. The watch is not merely blue in the ordinary sense, however, because its case, lugs, buckle, and dial components achieve their color through De Bethune’s painstaking thermal treatment of titanium. For Zuckerberg, the choice carries an added layer of personal significance because blue has long been the color he sees most clearly.
Zuckerberg is red-green color-blind, and his unusual relationship with blue has been intertwined with his companies from the beginning. In a 2010 New Yorker profile, he explained why blue became Facebook’s defining color, saying, “Blue is the richest color for me—I can see all of blue.” More than a decade later, Meta continues to use blue prominently across its visual identity, making the color an unmistakable part of Zuckerberg’s professional world. That makes his decision to wear perhaps one of the most extravagantly blue watches imaginable feel almost perfectly on brand. De Bethune, too, has made blue something of a signature, although its approach to achieving the color is far more complicated than simply applying a finish.
The DB28xs Kind of Blue Tourbillon uses a mirror-polished grade 5 titanium case that is subjected to carefully controlled thermal oxidation, creating an extremely thin oxide layer that produces the vivid metallic blue through its interaction with light. Depending on the angle and surrounding light, the color can move between electric cobalt and deep navy, giving the 38.7mm case an almost otherworldly appearance.
The process is notoriously unforgiving, with even individual screws potentially being discarded if their color does not match precisely. Denis Flageollet, De Bethune’s co-founder and technical mastermind, reportedly discovered the extraordinary effect while experimenting with titanium balance wheels at temperatures above 700 degrees Celsius.
Beneath all that blue is an equally remarkable piece of watchmaking. The hand-wound DB2009V7 movement houses a 63-component tourbillon cage that weighs only 0.18 grams and completes a rotation every 30 seconds, twice as quickly as the traditional one-minute tourbillon. It operates at a high 5Hz frequency while still delivering five days of power reserve through two self-regulating barrels, an impressive combination of speed, energy efficiency, and miniaturization. De Bethune also managed to fit the entire mechanism into an architecture measuring only 8mm thick, making this the first time its tourbillon had been placed inside the compact DB28xs format.
The result is a $225,000 watch that feels unusually appropriate for Zuckerberg. While its technical credentials would be enough to make it extraordinary on their own, its overwhelming blue character gives it a more personal connection to the man wearing it. As Zuckerberg spoke about the future of autonomous AI, his wrist quietly offered a reminder of a much older part of his story, the color that he has always been able to see best.
