Entirely dressed in blue, the new Audemars Piguet Royal Oak Perpetual Calendar in 41 mm introduces the Manufacture’s first case and bracelet fully crafted in blue ceramic. The matching blue Grande Tapisserie dial and subdials further bestow the timepiece with an air of starlit sky.
The new, blue Royal Oak Perpetual Calendar is mostly identical to its predecessors, sharing an identical ultra-thin self-winding movement (caliber 5134) and case profile (41mm × 9.5mm), with the only major updates coming in the form of the high-tech blue ceramic case and the matching blue color of the grande tapisserie dial.

The blue-ceramic Royal Oak Perpetual Calendar brings out the best of both of those qualities, combining the ultra-hard ceramic material and aggressive styling with the same high-grade movement and the same delicate brushing and polishing of the case and bracelet that Royal Oak collectors expect.
Since its debut way back in 1972, the Audemars Piguet Royal Oak watch has been released in a dizzying array of ceramic cases. The Swiss watchmaker has now unveiled the first Royal Oak Perpetual Calendar to be crafted entirely in vibrant blue ceramic. The new model—Ref. 26579CS—dons the Smurf-like hue across its 41 mm case and matching bracelet. The color also saturates the signature Royal Oak grande tapisserie dial, with day, date, month, moon phase and leap-year indicators. Even the inner bezel is highlighted with the shade. For a touch of contrast, 18-carat white gold applied hour-markers and hands accent the piece with luminescent coating for visibility. To achieve the electric-blue hue, Zirconium Oxide powder—modified to obtain a blue pigmentation once baked—is mixed with “binder content” before being transformed into ceramic via a machining process, according to the watchmaker. The components achieve their final color once they have been sintered at more than 1,400 degrees Celsius. The Le Brassus-based artisans also hand-finished each ceramic component the same way they would precious metals. That means AP’s trademark satin-brushing and polished chamfers have been applied, painstakingly by hand, for a “play of light” that is intended to enhance both the ceramic and overall design of the blue Royal Oak timepiece. Inside, the new piece houses the extra-thin, self-winding Calibre 5134 shared by all current Royal Oak Perpetual Calendars. The movement automatically considers the number of days in the month while correctly displaying the current date, even in leap years. As long as the piece is regularly wound, it won’t need manual adjusting until the bonkers year of 2100, to stay in line with the Gregorian calendar. The movement was launched in 2015 and includes a 22-carat gold openworked oscillating weight. Decorations adorning the Calibre, like circular graining and sunray brushing, can be seen from the caseback.