Continuity mistake: In the scene where Dakota is having sex with Aubrey's boyfriend, it specifically shows that her bra is off. Once they finish, and she is getting off of him, she is covering her chest with the sheet. When she does this, her side isn't covered and you can that she is now wearing a black bra.
Continuity mistake: When Dakota is at the strip club, she has on high heels. They then change to black boots.
Continuity mistake: When the guy at the start takes off his T-shirt there is no tattoo. Then the tattoo appears. (00:11:40)
Answer: Blue's the color for Aubrey's character, and the red one's for Dakota. If you watch the movie carefully you can notice that Aubrey wears blue clothes the most of the time while Dakota wears red ones. So it's just to represent the diferent characters and make the movie obvious.