Platinum gets exactly one gradient dial and this is it. The Day-Date offers four ombre grounds across the range and each belongs to a single metal: brown ombre and slate ombre to Everose, green ombre to yellow gold, and blue ombre to the cool metals, platinum and white gold. None of the four crosses the temperature line and none of them shares a case with another. So a buyer who wants a graded dial on platinum has no choice to make about which gradient, only about the size and whether stones go into it, and at 40mm the set version does not exist either. This configuration is the only graded platinum Day-Date the larger case offers.
The ground is a single blue laid so its density rises continuously from the middle of the dial toward the rim, with no seam anywhere along the transition. Blue carries the treatment better than the other three colors the model applies it to, because blue holds its identity across a wide range of values and a pale blue and a deep blue both read plainly as blue, so the gradient registers as one color gaining weight rather than as two colors meeting. At 40mm there is more distance for that transition to cover, which works in its favor: a longer run from center to rim makes the progression smoother and the endpoints further apart, and the effect is more legible than the same ground at 36mm. The markers are applied Roman numerals in white gold, tall and narrow with fine serifs, standing proud with polished faces. They sit where the ground has already begun to darken, which is why they hold their edges without stones or outlines. The case is 40mm in platinum with the flat wide lugs and low band standard to the model, the bezel is fluted, and the President bracelet closes it in polished three-piece links. Fluting also interacts with a gradient in a way it does not with a flat ground. The ring reflects inward, dropping a band of brightness onto the outer edge of the dial, and that is exactly where an ombre is at its darkest. The result is a thin lift at the rim that makes the transition look slightly steeper than it is, so the gradient reads with more depth on a fluted reference than on a set one, where a continuous ring of stones floods the same area evenly.
A graded ground creates a problem in the apertures that no flat dial has. The day and date discs are printed in a single value, and a dial whose color changes continuously offers no single value for them to match, so whatever is chosen can agree with the ground at exactly one radius and must differ everywhere else. Both openings sit well out toward the rim where the gradient has deepened, so the discs read slightly lighter than the ground immediately around them. The frames absorb that difference and mark the boundary firmly enough that the eye reads two deliberate insets rather than a mismatch. The day is written out in full at twelve in words rather than shortened to three letters, which fixes the arc's width across every reference in the model. Both discs change instantaneously at midnight rather than creeping through the hour before, and the movement runs roughly seventy hours off a full wind. The numeral ring carries one interruption and the eye learns to expect it. The character at three gives way to the date window, so the sequence is broken at a single point while the day arc at twelve sits above the ring rather than displacing anything. On a graded dial that asymmetry is easier to absorb than it would be on a flat one, because the ground is already changing across the surface and the eye is not looking for uniformity. Setting runs through the crown alone.
Blue ombre is one of only five grounds that appear on platinum at both case sizes, alongside white, mother-of-pearl set with diamonds and ice blue in both its forms. That makes it useful for comparing the two diameters directly, and it is more useful than the others for the purpose, because a gradient shows what a change in area does to a dial more clearly than a flat color can. The ground behaves differently in its two forms as well: plain, it reaches both sizes; set with diamonds, it contracts to 36mm and appears on no 40mm reference in any metal. Every ombre in the range takes Roman numerals and nothing else, here and on all three of the others, so the marker treatment was never a decision available to the buyer. Two references carry the 40mm platinum roster, this one with a fluted bezel and 228396TBR with a set one. Blue ombre also has a white gold twin at this size, since the ground is shared between the two cool metals and both of them carry it on a fluted and a set reference. That gives the dial four homes at 40mm. The other three gradients each belong to a single metal and appear on fewer references as a result. Blue is the one the model distributed most widely.
A plain gradient under a fluted bezel is the configuration that lets the dial do all of the work, and on this ground that is the right division. Stones set into an ombre dial land in the middle of the transition, exactly where the gradient is smoothest and there is nothing to interrupt, so the set version gives up part of what makes the ground worth having. Here nothing interrupts it. The transition runs unbroken from the center to the rim and the only fixed elements on the dial are the numerals and the two apertures. Collectors who want color on a platinum Day-Date have a short list to work from, since the metal takes ice blue, bright blue, olive green and this, and of those only this one changes across its own surface. For a buyer who wants a dial that resolves differently depending on the light, it is the only platinum option at this size.
