Rolex Datejust 31 Yellow Rolesor — Blue Index Dial | Ref. 178243

Reference 178243 represents the Datejust 31 in one of its most classically appealing configurations: Yellow Rolesor construction paired with a blue index dial. Blue and yellow gold is a pairing with deep roots in Rolex's history — the combination possesses an inherent visual logic, the richness of 18 ct yellow gold complementing the clean, sky-like depth of a blue dial in a way that resists trend and anchors itself in timeless watchmaking convention.

Yellow Rolesor combines an Oystersteel case with 18 ct yellow gold bezel, crown, and bracelet outer links, bringing precious-metal presence without committing fully to a yellow gold case. The 31 mm Oyster case maintains Rolex's 100-metre water resistance, built around the screwed-down Triplock or Twinlock crown system and a solid caseback. The Calibre 2235 automatic movement — the predecessor to today's 2236 — provides reliable, COSC-certified timekeeping, driven by a self-winding rotor and offering a power reserve of approximately 48 hours. The blue dial, likely lacquered and set with applied yellow gold index markers, achieves its depth through a multi-step finishing process.

The 178243 occupies an interesting position in the secondary market: it predates the 2236-generation 278xxx references but offers essentially the same proportions and aesthetic DNA. Collectors who prefer the slightly older reference — or who find the 178xxx generation better suited to their wrist — often cite the Yellow Rolesor blue dial combination as one of the most satisfying executions in the 31 mm Datejust canon. It is a watch that wears its intentions lightly and ages with uncommon grace.