Perfectly positioned between Greenwich and Rye on a quiet cul-de-sac within the highly coveted Greyrock on the Sound enclave, this custom 2026 center-hall Colonial delivers an immediate luxury lifestyle and architectural prominence. Masterfully engineered with an emphasis on advanced sound insulation and grand interior proportions, this 3,800-square-foot layout is a brilliant masterpiece of modern, open-concept, flexible design, purpose-built to serve as a quiet, self-contained sanctuary. A striking double-height foyer flows seamlessly into an expansive open-concept great room drenched in radiant natural light. The gourmet chef’s kitchen stands as the home's anchor, meticulously appointed with a premium quartz island, farmhouse sink, and high-end integrated appliances. This space transitions effortlessly into a spacious family room anchored by a custom gas fireplace, creating an intimate, inward-facing entertainment haven. A formal dining room adorned with a coffered ceiling and a dedicated private home office provide ultimate lifestyle flexibility. Upstairs, the sprawling floor plan features a serene primary retreat boasting dual vanities, a makeup station, and a custom-crafted walk-in closet. Three additional generously sized bedrooms, two full bathrooms, and a second-floor laundry room offer ample living space. The crown jewel of this level is the spectacular bonus room wrapped in a panoramic wall of windows. Drenched in exceptional daylight, this vast and versatile space serves as a magnificent second family room, an inspiring creative studio, or an elevated playroom. Bring your vision to life in the massive, unfinished 1,650-square-foot walk-out lower level, meticulously prepped and engineered for an effortless future finish. Featuring soaring 10-foot ceilings and rough-in plumbing already in place, this thoughtfully configured, exceptional layout provides the ultimate turnkey canvas. It is primed for immediate transformation into a custom home theater, high-end golf simulator, or a dedicated fitness studio, secondary home office, and full spa bathroom. Outside, the property rests on a generous 0.86-acre lot wrapped in dense, multi-layered perimeter landscaping. This intentional, engineered green buffer creates a profound sense of structural serenity and peaceful seclusion. Complete with a classic Belgian block driveway and a premium 2-car attached garage, this property represents unrivaled turn-key convenience—located just steps from your private neighborhood beach & deep-water dock, and minutes from the premier public beaches, elite clubs, and commuting hubs of the Sound Shore.