Dragonborn are descendants of the the Ten Great Dragons and thus come in ten colors. Scholars have noted the oddity that when dragonborn of different colors have children, those children are always the same color as their mother, despite everything people know about how such things work.
Dragonborn are also the only race in the whorl to lay eggs like reptiles, although the actual egg-laying doesn't happen until after they're fertilized through sex like the other races.
It's also worth noting that despite the inaccuracies spread by certain human-centric artists, dragonborn females do not have mammalian breasts, nor do they nurse their young. In fact, the best way to tell males and females apart is dragonborn females tend to be physically larger and stronger.
Dragonborn are spread more or less evenly across the Whorl. They do predominate in the island fortress-city of Lankha which is ruled by a dragonborn council representing each color, and they are practically absent from Ayodhya where they are banned by edict of the Immortal Solar Emperor.