Ginger
No one understood why the Doctor wanted to be ginger. Rose had asked him about it, but he didn't explain. That night, after Rose had gone to bed, the Doctor stood in the control room of the TARDIS, thinking about Gallifrey and the family he lost. He knelt on the floor of the TARDIS, and he removed the grate above the chest where he kept the mementos from his long life and many adventures. From underneath a Cyberman's chest plate, the globe containing the Carrionites, the head of a Roman statue, and an Agatha Christie book he pulls a box of pictures. The box is old and battered, covered in scars from defending its precious contents: inside the box are pictures of his family. He sifts through the pile of pictures, pictures of his wife Evelyn, eldest son Alexander Bishop and his wife Karina, his youngest twin sons Mica and Jeremy Bishop, and finally pictures of his only daughter, Myrabelle Storm, and her husband Kyan Storm.
Myrabelle is the reason he wants to be ginger. Myrabelle's first incarnation was blonde and blue eyed, and she hated it. There was an accident, a bullet in the back of her skull, when she was a teen. When Myrabelle woke up in her bedroom, she went over to her dresser, looked in the mirror, and smiled the brightest smile the Doctor had ever seen on her face. Her eyes were still blue, but her hair was a gorgeous, deep red.
The Doctor called Myrabelle his "blue sky" because of her ability to cheer him up when no one or nothing else could. She was the pride of Gallifrey, rising through the ranks of the Gallifreyan navy to be the youngest General ever. Her ship was called the "Blue Sky" because of her father's nickname for her. Sadly, she disappeared during the Time War, and the Doctor could only assume she was dead, and her infant son Matthew as well. It was well known that Kyan was dead, as there were multiple witnesses to Kyan's brother's betrayal. His brother was jealous of Kyan's relationship with Myra, and wanted her for himself.
The Doctor was not a man given to showing emotion, but looking at the pictures of his little girl and the grandson he never got to meet caused a clenching of his heart. A single tear rolled down his new face, and he continued to look through the pictures. This was how Rose found him the next morning, sitting in the control room, looking at the reason he wanted to be ginger.