This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Skin
[{'content': 'Gradual lightening / blue black colour shift in a tattoo is called: \nSelect and explain. \nA. Tyndall effect, B. Halo effect, C. Washing out, D. Leaching', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Changes in tattoo maturation Halo effect - extrusion of pigment on deposition near follicle Washing out / leaching/pigment migration-carrying away of pigment by macrophages on deep inseion Ref: Textbook of dermatosurgery & cosmetology, satish S savant, E-2,P-338.', 'role': 'assistant'}]