Design an elegant palace-style exterior with a monochromatic all-grey color scheme. The building should have grand architecture with tall, ornate columns, intricate grey stonework, and large windows with grey frames. The facade should be luxurious, featuring marble-like grey textures and subtle grey accents throughout. Include a large, elaborate entrance with double grey doors framed by grey decorative arches. Surround the building with grey stone pathways, manicured gardens, and a grand grey staircase leading to the entrance. Include grey iron railings on balconies to complete the royal, monochrome look