Paired with a knit tie and a suit, a blue striped shirt will make you the star of every wedding you're invited to without stepping on the happy couple's toes. Like a plain white tee or a pair of trusty dark jeans, the blue striped shirt is a sartorial skeleton key you can use to unlock any outfit. To prove it, here are 15 objectively perfect versions—in a myriad of stripes, shades, and price points—to help kick off your blue period in style.