adidas released the Ultra Boost 4.0 'Core Black' in November 2016. The fourth iteration of adidas’ performance runner takes on a solid black Primeknit upper, complemented by yet more black on the midfoot cage, heel counter and Stretchweb rubber outsole. The contrasting white Boost midsole features a grey insert on the medial side, the only element that strays from the shoe’s black-and-white theme.