The Auburn Prince (The Lamentation of Cin'Cline, #6.1)

After Clementine Aurelius' parents vanish–forcing her to live with her abusive Aunt Dahlia–a handkerchief given to her in the aftermath of that trauma isn't just a nostalgic memento of the past, but a clue to an otherworldly conspiracy and a looming war. To learn the truth about her parents, the resilient thirteen-year-old must journey into Mundialis, a land where possessing color is a privilege, and with the aid of the cursed Fox Prince, talking beagle, and a magical gecko, must overcome her emotional solitude and defeat a neglect-born malevolence that infinitely whispers, "There is the you and the I, the known and the Other, and nothing else beside that."