By now, the MB&F Legacy Machine Perpetual has earned the right to be called a modern independent watchmaking landmark. First introduced in 2015, it meant a full recalibration of one of horology’s most revered complications. For 2026, MB&F returns to that extraordinary mechanism with the LM Perpetual Chromatic Editions, three jewel-set versions that add colour without compromising the clarity of the original idea.
There are two white-gold editions, one with blue sapphires and one with purple sapphires, and a red-gold version set with rubies. Each bezel carries 48 baguette-cut stones, hand-set by STG Creation in Geneva, framing the open architecture of the movement without increasing the 44mm case diameter. The matching PVD-treated hands, blue, purple or 5N for the ruby version, give the watches a pleasing sense of coherence rather than afterthought glamour.
The important point, however, is that the stones are not doing the heavy lifting. Beneath the colour remains Stephen McDonnell’s remarkable perpetual calendar, a 581-component, fully integrated calibre built for MB&F from a blank sheet of paper. Conventional perpetual calendars tend to assume a 31-day month and then skip through the redundant dates when necessary. McDonnell’s “mechanical processor” reverses that logic, starting from a 28-day month and adding only the required extra days. It is clever, practical and deeply MB&F: dramatic in presentation, serious in engineering.
Blue sapphire edition: set in 18kt white gold framed by 48 baguette-cut blue sapphires from Madagascar/ Sri Lanka and blue PVD-treated hands.
Red ruby edition: set in 18kt red gold with 48 baguette-cut Mozambique rubies and 5N PVD-treated hands echoing the colour of the case.
Purple sapphire edition: set in 18kt white gold, with a bezel of 48 baguette-cut purple sapphires.
That duality has always defined the Legacy Machines. Where the Horological Machines look to science fiction, aviation, cars and childhood imagination, the Legacy Machine line was Max Büsser’s counterfactual fantasy: what might he have created had he been born in 1867 rather than 1967, inspired not by Star Wars or fighter jets, but by pocket watches, the Eiffel Tower and Jules Verne? The answer was round, three-dimensional and historically aware.
The LM Perpetual Chromatic Editions sit neatly inside that philosophy. The suspended balance still dominates the dial like a miniature kinetic monument; the subdials still appear to float above the movement; the calendar indications remain legible despite the mechanical density below. The gemstones bring a touch of flamboyance and soften the intellectual severity of the LM Perpetual.
Limited to just eight pieces per colour, these are among the rarest LM Perpetuals made, and perhaps the most celebratory; a vivid reminder of why the original was such a milestone in contemporary. horology.
Author: Julia Pasarón
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