The coastal retreat theme brings airy ocean elegance and natural beach textures into the guest bathroom using soft blues, crisp whites, and warm natural fibers. This design features light seafoam green or sky blue walls paired with classic white beadboard or shiplap wainscoting covering the lower half of the walls. Woven seagrass accent baskets, rattan-framed mirrors, and natural jute rugs introduce organic warmth and tactile texture to cold tile surfaces. Warm brushed brass or polished chrome hardware adds a nautical sheen that elevates natural materials into a refined aesthetic. The color palette draws inspiration from coastal landscapes, combining sandy beige, soft aqua, faded navy, and bright porcelain white. This relaxed, sunlit visual approach works exceptionally well for coastal cottages, summer guest suites, or beach-inspired suburban powder rooms.