Designers aimed for a soothing, sophisticated California bungalow ambience in the lobby, using a palette of sandstone, mahogany and muted teal tones. The interior of the 106-room hotel is a visual departure from the bustling, brassy casino next door, said John Martino, director of operations. This valley of vineyards and horse ranches will get an injection of cosmopolitan flair this week with the grand opening of the Chumash Casino Resort’s upscale hotel, the latest phase of a much-contested $150-million expansion.