Now it's the right time to start wearing that unconstructed jacket of yours or buy a new one.
An unconstructed jacket looks the best with chinos, jeans or white pants, but for the brave ones; I recommend giving it a try with a pair of shorts. With shoes I would probably go for brown suede or leather.
They sell these bad boys in every imaginable color now a days; navy and white are classics, but light pastel colors are cool too.
I really like how Japanese men mix classic Italian style with preppy, and give it even more flavor with Japanese style, sometimes even with Japanese fashion brands such as 45rpm, Number (N)ine and Miharayasuhiro