Cobalt Blue is a 2013 fictional drama novel by Indian film director, screenwriter and playwright Sachin Kundalkar. It was the debut novel of Kundalkar and first published in 2006 in Marathi language, it was re-released in English in 2013 with translation by Jerry Pinto. The story follows two siblings, Tanay and Anuja who fall in love with the same young man who comes to stay at their house in Pune as a paying guest. The novel deals with the theme of sexuality, family and society.