Baby Blue has a white coat, a baby blue kind of color for her mane and purple eyes. Her cutie mark was not seen in the episode she appeared in or it could mean that she hasn't obtainted her cutie mark yet. Her fan-made name was given to her due to the color of her mane and she being a filly.
Baby Blue has only made one appearance in the whole My Little Pony: Friendship is Magic series.
Baby Blue shares her design and colour scheme with Cotton Cloudy.