Her afro and darker skin (coupled with a white mark around her eye, rather than a black one) make her distinct from most on-page incarnations of Domino, but her spunky attitude and badass power set (which became far more cinematic than Wade would’ve anticipated) helped establish her for mainstream audiences.
Of course, in the end, we got Zazie Beetz in the role, and her version of Domino became a widely-praised element of the film.
That, along with Beetz’s own ability to trade barbs with Ryan Reynolds (who is already no slouch in the smartass one-liner department) made her a standout in a film full of standouts.