Red brown post moem staining is seen in -
Poison Color Nitrites Reddish brown Potassium chlorate Chocolate brown Phosphorus Dark brown Hydrogen sulphide Bluish green Cyanide Cherry red Carbon monoxide Pink Opium Blackish Ref: K.S.Narayan Reddy's Synopsis of Forensic Medicine and Toxicology , 29th edition.
Dhatura
Aniline
CO
Nitrites
Poisoning