One of the LDS missionaries that visits the house is wearing a light blue shirt. LDS missionaries are only permitted to wear non-decorative white shirts with dark pants/suits, and a conservative tie. The missionaries also carried no pamphlets, visual aids, appointment books, or their own complete sets of scriptures, which is highly unlikely for door-to-door proselytizing.
Throughout the film Blake plays guitar both left handed and right handed. (Kurt Cobain - on whom Blake is reportedly based - played left handed.)