Marvel Studios isn't limiting it's search for Iron Fist to Caucasian actors, according to The Hollywood Reporter. Marvel has held tryouts for both Caucasian males and Asian-American males according to the Hollywood trade.
In comic books, Iron Fist is Danny Rand, a Caucasian boy who is orphaned on the doorstep of a mystical land called K'un L'un. He's taken in and taught the ways of being an Iron Fist, ultimately becoming one himself.
Iron Fist has been in development through Marvel for over a decade, starting life as a feature film in which Scottish martial artist and actor Ray Park, best known as Toad from X-Men and Darth Maul from Star Wars was cast as the lead.
No release date has been set for Iron Fist.