Rubber sole The adidas Yeezy Boost 350 V2 "Butter" stays true to its nickname by being one of the smoothest sneakers out. Released in summer 2018, the adidas Yeezy Boost 350 V2 "Butter" has a pale yellow hue on the Primeknit upper. A semi-translucent midsole in the same color is paired with a slightly darker shade on the outsole. The absence of the model's traditional side stripes lends a more minimal look.