The new Saguaro hotel in Palm Springs, California, is a riot of bold color that pays homage to the swinging midcentury vibe of this desert oasis town. The only rule that renowned architects Peter Stamberg and Paul Aferiat seem to have followed in reimagining this old Holiday Inn was: The more the better. The colors are bright, layered and fearless. They also have a way of putting you in a good mood, a vacation mood. The kind of mood that calls for a drink with a little umbrella.