Oak released as part of their in-house label the "Sunglass" t-shirt. The white premium cotton t-shirt features an over-sized sunglass print on the front. Not the first time you have seen that, but Oak adds a little something to it. The shirt was printed with UV reactive ink, which makes the sunglasses change color, when exposed to the sun.
You have to pick it up quick if you still want to make use of it though!