Didi Gregorius is Stance’s second MLB contract guy (Jon Jay is the first), and he’s taking full advantage. Stance made mismatched socks cool, and a lot of guys (Bryce included) wore “The 4th” Stars and Stripes style as intended, but Didi wasn’t feeling it so he doubled up on the stars sock.
These things sold out in an instant, but you can shop similar options at the link.
He also wears the standard Yankees blue, which somehow aren’t available but many Yanks styles are.