Designer Ann Lowengart and architect Jeffrey Graham thoughtfully curated pieces in this Los Altos house to reflect the wife’s love of classic design. In the foyer, Galbraith & Paul’s tone-on-tone Fern wallpaper creates the perfect backdrop for a vintage seashell-encrusted mirror and a drop-leaf, George III-style Pembroke table from Antique & Art Exchange. A Lee Jofa rug delivers subtle color.