The series is based on the popular New York Times bestselling book series collectively known as The Expanse,  written by Daniel Abraham and Ty Franck (under the pen name James S. A. Corey). Abraham and Franck will be show producers.
A tortoiseshell cat is a coat color where the cat is a molted brown cat with black, reddish, or orange patches. They can also have white paws. Tortoiseshell cats have unique genetics. The vast majority of tortoiseshell cats are female, because two X chromosomes are required to produce black, gold and orange coloring.
1 Others consider tortoiseshell cats to be tricolor cats as well; however, their coat patterns do not display the three colors as distinctly as calicos do.  Bicolor cats show two distinct colors, one of them being white. Tuxedo cats, with their beautiful black and white coats are examples of bicolor cats.