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

Reference 178243 pairs the enduring two-tone appeal of Yellow Rolesor with a clean black index dial — one of the most versatile dial configurations in the Datejust range. The combination of Oystersteel and 18ct yellow gold runs from the domed bezel through the Jubilee bracelet, creating visual continuity that has remained commercially relevant since Rolex introduced two-tone construction to the Datejust in the 1970s. The black dial provides a degree of formality and contrast that the lighter silver and champagne variants do not offer.

Inside, the 178243 carries the Calibre 2236, Rolex's in-house movement purpose-built for the 31mm case diameter. Incorporating the proprietary Syloxi silicon hairspring — developed by Rolex's materials science division — the 2236 delivers 55 hours of autonomy and COSC chronometric performance while eliminating the magnetic vulnerability of traditional Nivarox hairsprings. The domed bezel of the 178243 variant offers a smooth, classic profile that complements the dressy character of the black dial.

The 178xxx Datejust 31 series, produced over roughly a decade before the transition to the current 278xxx references, represents a well-established and broadly supported generation. The black dial configuration with Yellow Rolesor has proven consistently popular in the secondary market, maintaining value through its broad wearability and timeless two-tone aesthetic.