Green blue postmoem discoloration is seen in which poisoning -
Cyanide
Carbon monoxide
Phosphorous
Hydrogen sulphide
The colour of postmoem hypostasis in hydrogen sulphide poisoning is bluish green. It is an asphyxiant which inhibits cytochrome oxidase. Dr.Narayana Reddys Synopsis of Forensic Medicine and Toxicology 27th edition pg. 76,313.
Death and postmortem changes