In case you missed it, Nike has taken over the rights to outfit the NBA with uniforms this season. In some cases (like the Timberwolves) that has led to drastic changes. In other cases, like the Celtics, the changes are much more subtle.
There will actually be 4 “new” uniforms for each team and Nike is slowly rolling them out to maximize the publicity (brilliant marketing angle in the dead August days). The first two are generally going to be much like the team’s normal home and away jerseys (though teams have the option of picking whatever colors they want regardless of venue this year).