Now that we've had some time to think it over, it's pretty clear the color blue has been just as significant as the number 4 to this couple.
Jay-Z is known for his blue Yankee fitteds, and has even laced his career with the color. Take for instance his album titles such as The Blueprint and his classic lines like "My favorite hue is Jay-Z blue."
This dynamic duo isn't the first celebs to take their bond with colors into their personal life.
Check out what vibrant colors have been the inspiration behind the names of other hip-pop celeb babies in the gallery above.