Slate is the one dial here that neither joins the case nor argues with it. Reference 278285RBR is the 31mm Datejust in solid Everose gold with a bezel set with diamonds, and this configuration pairs it with a slate dial and applied index markers, on the President bracelet. Chocolate and rose-colored dials extend the warmth of the metal, white refuses it outright and aubergine opposes it, and slate simply sits at a distance, a grey with enough warmth in it to avoid reading as cold and not enough to read as related. It is the most ambiguous configuration on the reference and the one that changes most between a photograph and a wrist.
That ambiguity is a property of the color rather than an accident of it. Slate carries a sunray finish, fine radial brushing worked outward from the center, so the dial brightens and darkens as the wrist rotates rather than holding one value the way a flat lacquer would, and against a warm case it picks up more of that warmth at some angles than at others. The applied indexes are Everose and faceted along their length, drawn for this case size rather than scaled from a larger one, and they carry no information beyond position, which leaves the relationship between dial and case as the only thing on the watch to consider. The case is solid Everose rather than a two-metal combination, uniform from the lugs through the bracelet and considerably denser than steel, so the watch carries noticeably more mass than its size suggests. Everose is Rolex's own rose gold, cast in the brand's foundry and introduced in 2005, with a small proportion of platinum that stops the color drifting toward yellow across decades. The bezel stones are seated individually into recesses cut in the gold rather than dropped into a preformed channel, and on a ring this small there is less circumference to absorb an error. The bracelet is the President, semi-circular three-piece links with a concealed clasp folded away so completely that the bracelet appears continuous from every angle. The date sits at three under the Cyclops lens on a disc matched to the dial, its frame polished and level with the surface. Sunray finishing is applied as fine radial brushing from the center outward, and on a dial this close in temperature to its case the effect is to make the relationship between the two shift rather than hold.
The Datejust shows the date and nothing else. 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. The Cyclops lens above it has been part of the model since 1953 and magnifies the date roughly two and a half times, which makes a small window readable without enlarging it and unbalancing the dial. 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, since a smaller barrel has less room to store energy and a proportionally smaller rotor gathers less of it. The rotor winds in both directions rather than only one, which lets a movement this size keep itself running on the wrist movement of an ordinary day. The crown screws down against the case, and Rolex draws the bracelet to taper from the lugs toward the clasp so the mass sits forward on the wrist. 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. Slate has appeared across several generations of the model without ever being the volume seller, which is part of why it still reads as a chosen dial rather than a default one, and it is one of the few grounds Rolex offers with a sunray finish rather than a flat lacquer. Everose arrived in 2005 and has become the metal most closely associated with the model. Solid gold references are built in far smaller numbers than the steel and two-metal ones. The President bracelet was designed in 1956 for the Day-Date and appears here as a borrowing. Within the generation, 278285RBR is the solid Everose reference with a diamond-set bezel. Slate has also appeared on every metal Rolex builds the model in, which is unusual for a ground in the current range and part of why it reads as independent of whatever case it is fitted to. Slate is one of two grounds at this reference the catalogue lists both plain and set, rose being the other, and its set version takes a large Roman six carrying eleven stones.
The buyer for this wants a warm watch without a warm dial and does not want the dial fighting the case to achieve it. Slate is the only ground on the reference that manages that, staying independent of the metal without opposing it, which gives the watch a neutrality that none of the matched or contrasting dials can offer. The sunray finish is the other argument, since it means the dial is doing something as the wrist moves while every other unset configuration here holds still. It is also among the harder dials on the reference to judge from images, because a photograph fixes one angle of a surface designed to change across several. Buyers who found the chocolate and rose-colored dials too matched and the white one too severe generally arrive here, which makes it the compromise choice on the reference in the best sense of the word. Seven grounds are built here and six of them carry stones, so an unset dial narrows the field to three.
