Rolex Datejust 31 White Rolesor — Dark Grey Roman Dial | Ref. 278240

Reference 278240 introduces the 278xxx generation Datejust 31 in White Rolesor — a 31 mm case that bridges the gap between the Lady-Datejust 28 and the Datejust 36, appealing to wearers who prefer a mid-sized presence on the wrist. White Rolesor, combining Oystersteel with 18 ct white gold for the bezel, crown, and bracelet centre links, delivers a cool, precious-metal accent without the full commitment of an all-white-gold case.

Calibre 2236 is the movement of record for the 278xxx Datejust 31. This in-house automatic calibre, developed specifically for mid-sized Rolex references, incorporates a silicon Syloxi hairspring offering superior resistance to magnetic fields and temperature variation. A 55-hour power reserve and COSC chronometer certification underline its technical credentials. The dark grey dial with Roman numeral hour markers provides a sophisticated contrast against the white Rolesor construction, the numeral choice adding a classical formality to the 31 mm format.

For collectors and wearers, the 278240 represents a thoughtful middle ground: modern movement technology in a versatile case size with understated two-tone materials. The dark grey dial is among the more distinctive colour options in the Datejust 31 range, offering market differentiation from the more common white and silver configurations. Strong new-production availability means the secondary premium remains modest, favouring buyers seeking value alongside refinement.