Only then she will gain the option for another horse. Serana will ride a skeletal horse, until the Dawnguard questline has been completed. Horse types and armor that have been hand-picked through the dialogue options will remain the same throughout the entire game. The color of a follower's horse can be chosen each individually by talking to them, or they all can be set to a uniform color via the configuration menu (PC). (PC: This feature is available in the configuration menu, and is by default disabled.) The follower(s) will mount and dismount when the Dragonborn does. The horse will be named for example 'Lydia's horse', and cannot be ridden by anyone else but the owner of that horse. The Dragonborn does not have to acquire a horse for them, however, as they will summon their own horse.
