Officially the home team wears white, with the away team wearing colors, but since the home team gets to decide what it wants to wear, that distinction makes little difference and most media references seem to call the white jersey for the away jersey.
I believe for football and hockey, the home uniform is colors, while for baseball and basketball, the home team is white.
However, since the NFL and NBA allow the home team to pick color or white (while NHL and MLB do not), it's merely tradition in the former two leagues.
In the NFL, the only two teams that wear white at home more often than not are DAL and MIA.
Interestingly, since the Dolphins introduced the throwbacks in 2015, when it's up to them, they have worn the aqua throwbacks more often than the aqua regulars. (I don't think home teams can wear throwbacks in International Series games...?)