There's one mystery on FX show "Louie" that has never really been addressed.

While Louie's ex-wife "Janet" is played by black, Jamaican actress Susan Kelechi Watson, his two daughters are very white, very blonde little girls.

Despite leaving viewers guessing about the backstory of the relationships, the race issue has never been fully explained on the show ó and that's intentional.

"We play around with ethnicities. Janet is African American, but both of their kids are white and Louieís white so how does that work? Look, it probably doesnít make sense but Louie wanted to cast someone to play his on-screen ex-wife who was unlike his real ex-wife," casting director Gayle Keller tells Business Insider. "He didnít want that much reality in this show."

But the race of the actress wasn't necessarily a premeditated decision, Louis just thought Watson was the best person for the part.

"We auditioned people who were African American and white, we auditioned both," explains Keller. "We didnít limit ourselves to someone who was just Caucasian. Louis just felt that the woman who we cast [Watson] was best for the part and she happened to be African American and he didnít care about that. He didnít feel like he had to explain that in any way and have two Caucasian children and an African American wife."

Watson talked to Essence magazine in 2012 of her confusion during the audition process:

"I'd seen the show before I auditioned so I knew the kids on the show. And they were White. So when I go into the audition I say, 'I don't know what part I'm auditioning for but I know it can't be his wife because I've seen his kids.' They were like, 'Okay, we're just gonna press record.' After I got the role I was still thinking it can't be to play his ex-wife, maybe his friend, but not the ex-wife. I just thought it was hilarious, and that Louis [C.K.] was kind of brilliant for casting it that way."

In 2012, Louis C.K. told Jimmy Kimmel: ďIf the character works for the show, I donít care about the race. When a black woman tells you to get a job, itís just more Ö Ē he added, trailing off with a laugh.

To make matters more confusing on the show, the "Janet" character was played by white actress Brooke Bloom in a season 4 flashback sequence.

Casting director Keller says she auditioned African American, Caucasian, and Asian actresses for the flashback role.

"Ethnicity is not what was important for that role," says Keller. "It was more about the fact that we wanted someone who just understood the character immediately. All of the actors who come in to audition go on tape and they only get the material when they get to the audition. Everything is a cold reading because Louis likes when actors are not that prepared and forced to go with their instincts." 

At the end of the latest season 4, Louie's very candid new girlfriend, played by Pamela Adlon, finally asks the question on everyone's minds, pointing out, "those kids canít come from that woman."

Louie vaguely responds by saying that Janet is biracial, giving no real explanation for his very white children.

"I think Pamelaís character, who she is as a person, to get into a relationship with Louie and see the children and see the ex-wife, she has the tenacity as a character to ask that question," says Keller. "Thatís just who she is and sheís not going to let that go by without commenting about it." 

While writer Dustin Rowles says Louis C.K. is "just f------ with us" when it comes to the interchangeable races of roles, Watson, who plays "Janet" on the show, told Essence:

"I think people have found it to be a lot like what Louis' been saying all along. If you follow the show you understand that there's no real continuity, and that Louis is a bit of a maverick in terms of not having any allegiance to doing something one way. People see it and go, 'What? This makes no sense.' And then they go, 'Oh, that's 'cause we're watching Louis.' And they take it with a grain of salt.

I think it's remarkable because for so long we've been saying we just want to see each other as human beings. Our culture is very important, of course, but this feels like a moment where someone has said, 'Your culture is irrelevant at this moment. It's more about whether you feel like you're right for this role and what you're bringing to it.

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