Nothing on this dial moves except the stones. Reference 278243 is the 31mm Datejust in a combination of stainless steel and yellow gold with a domed yellow gold bezel, and this configuration carries a dark grey dial set with diamond markers and no numerals at all, on the Oyster bracelet. The ground is matte and holds a single value in every light, there is no marker set to read past, and the diamonds sit against it as twelve isolated points that change while everything around them stays exactly as it was. It is the most concentrated a set dial gets on this reference.
That isolation is a function of the ground rather than the stones. On a reflective dial the markers and the surface change together and the eye reads them as a single shifting field, and a matte dark ground separates the two completely, so each diamond registers as a discrete event rather than as part of a general brightness. Dark grey is the most neutral of the deep colors offered here, applied as an opaque lacquer in several thin coats so it stays even across a curved surface, cooler than chocolate and considerably lighter than aubergine. The markers stand slightly proud of the surface, and against this ground the setting nearly disappears while the stone does not, which is the reverse of what happens on a pale dial where the mount forms part of the marker's outline. Steel and yellow gold is the most visible two-metal pairing Rolex makes, since yellow gold sits nowhere near steel in color and every junction reads as a clear boundary between materials. The steel forms the case and the outer bracelet links while the gold takes the domed bezel, the crown, the bracelet center rows and the marker settings, and the gold is solid rather than plated or capped, which is why these bracelets hold their appearance across decades where most of the industry's two-tone watches do not. The bracelet is the Oyster, three broad flat links brushed across the top with polished flanks. The date sits at three under the Cyclops lens on a matched disc. Rolex keeps the settings low and tight against the dial, since a raised marker on a 31mm surface has little room before it starts to crowd the hands, and the hands themselves are polished yellow gold drawn for this case size rather than scaled from a larger one. The aperture frame is proportioned the same way, since a window drawn for a larger dial crowds a smaller one. Rolex also matches the height of the marker settings to the height of the date frame, so the dial reads as one plane with elements standing off it rather than as several plates at different levels.
Rolex matches the date disc to the dial rather than leaving a paler window in a darker surface, which decides whether the aperture belongs to the watch or interrupts it, and against a dark ground the magnified numeral carries as much contrast as a date display can be given. A single aperture also keeps the marker ring uninterrupted, since a second would break a pattern that depends on running continuously. The Cyclops lens above it has been part of the Datejust since 1953 and magnifies the date roughly two and a half times. The date changes instantaneously at midnight rather than creeping through the surrounding hour, the feature the Datejust introduced in 1945 and the one it takes its name from. Correction runs through the winding crown without moving the hands, and nothing the watch asks for requires a tool. The movement is self-winding with a power reserve of approximately 55 hours, an engineering result on a movement built to fit a 31mm case rather than a figure carried down the range. The rotor winds in both directions rather than only one. The crown screws down against the case, and the Oyster closes with a concealed clasp folded away inside the links. Correction takes seconds and requires no tool.
The Datejust arrived in 1945 as the first self-winding wristwatch to show the date in a window, and the 31mm case sits between the 28mm Lady-Datejust and the 36mm original. The 278000 generation replaced the 178000 series in 2018 with a revised case and bracelet. Rolex registered the name for its steel and gold construction in 1933, on the reasoning that steel supplies the structure and gold supplies the color. Dark grey has appeared across several generations of the model without ever being the volume seller, and the dark options are a recent departure from a range that ran to lighter colors for most of the model's history. Within the generation, 278243 is the steel and yellow gold reference with a domed bezel. Gem-set dials have been part of the model for most of its history, and the marker-only arrangement is the more common of the two forms Rolex offers on this reference. Dark grey is one of three grounds here built in two set arrangements, alongside olive green and silver, so each of the three takes four of the twenty-two rows where the other five grounds take two. Only champagne and white arrive unset at all on the reference.
The buyer for this wants the diamonds counted rather than diffused. On the silver equivalent the stones merge into a bright field and the effect is general, and here they stay separate and the effect is specific, so the dial reads as twelve stones rather than as a set watch. That is a meaningfully different proposition and it is the reason both versions exist. It is also the most legible of the marker-only dials on the reference, since the contrast between stone and ground is at its maximum, and the easiest of them to photograph accurately. It is the version to own if the stones are the reason for the watch rather than a feature of it. Buyers who found the silver marker dial too diffuse generally arrive here, and describe the difference as being able to see the stones rather than the shine. Eighteen of the twenty-two rows carry stones.
