Fashion-challenged engineer needs advice. I'm attending a classical music performance at a Santa Barbara Music College. The event starts at 3pm, reception following. The weather is likely to be very nice (~70F). I'm not wealthy but I expect many of the guests to be...., so curious to determine if an off-white Jacket with (blue?) polo shirt, Khaki trousers, and light-brown tan leather shoes are appropriate. I'd like to try and blend in but am concerned I will either under dress or over dress. Ideas for me?