Season 3 of "Orange Is the New Black" ended with the reveal that new inmates are coming in. Production for season 4 has already begun and a casting call, reported by Project Casting, gives a big clue on what to expect when the prison is populated by new inmates and what they might be like. 

According to the report, the actresses must be Dominican-type females. They must not have worked on the show in any capacity. This means they should not have been in previous seasons as extras or other background characters. Fans speculate that this means the inmates are going to prison for the first time in their lives, which could be why they shouldn't have appeared in the prison before. 

The casting call is also quite specific with how the girls should look. It requires that the actresses have no ear or facial piercings, no unnatural hair color which means no dye, and their hair should be at its natural look so no wigs, no dreads, no weaves or twists. Some fans speculate that the new characters could be conservative religious people. 

The scenes these characters will be in will be filmed in only two days: June 29 and 30. This hints that they may only be side characters or even just background extras, but given how television shows film their scenes, they could be minor recurring characters who pop up a few times in every other episode of season 4. 

"Orange Is the New Black" is based on the real-life story of Piper Kerman and her experience in an all-female prison. Season 4 doesn't have a specific premiere date at the time of writing, but given how the previous seasons premiered in summer, it is speculated that season 6 will be released around June 2016.