Audemars Piguet Royal Oak Chronograph 26240ST.OO.1320ST.01 Bleu Nuit 41mm

The Royal Oak Chronograph 26240ST.OO.1320ST.01 is the blue option for a buyer who wants the full 41mm steel chronograph format without a flat, monochrome face. Bleu Nuit Grande Tapisserie creates depth behind the three registers, so the display stays legible while the blue surface remains visible as a colour field. The brushed octagonal bezel and integrated steel bracelet keep that colour disciplined rather than decorative.

The chronograph layout changes the visual pace of the Royal Oak. It brings more information to the dial than a three-hand 15500 or 15510, yet the blue texture gives the registers a coherent setting instead of a busy backdrop. This is why the reference works with tailoring as well as casual clothing: the blue introduces personality, while the steel architecture retains the direct, angular line that defines the collection.

The black-dial 26240ST chronograph moves attention toward the bezel, case edges and bracelet. Bleu Nuit keeps more light and colour at the centre, making this version the stronger choice when the dial is meant to be recognised first. Both serve the same broad steel chronograph role, but they produce distinctly different visual results on the wrist.

APS Factory lists a Calibre 4401 clone chronograph platform. The buyer-facing point is the visible dial architecture: registers, hands and date display sit in a purposeful arrangement that gives the watch its technical character without sacrificing the Royal Oak’s clean outer silhouette.