It's an accent color. And it's a standard Nike color (varsity maize), not a seasonal yellow.
Plus, the wimby ones will have a seasonal blue more predominantly than the yellow on the white/black ones.
Yonex VCORE Tour 89 w/ Volkl Cyclone 18 @ 48
Yonex EZONE Ai 98 w/ Yonex PolyTour HS 125 @ 45