Forensic science / Andrew R.W. Jackson and Julie M. Jackson. -- 3rd ed. 2011

p. 217
The post-mortem examination of individuals who have died as a result of gas poisoning might reveal the likely identity of the gas responsible. For example, the unusual cherry-pink appearance of any post-mortem lividity indicates carbon monoxide poisoning while a deeper red coloration of this feature is sometimes observed in cases of cyanide poisoning

p. 380
One final point worth making is that in certain types of poisoning, the colouring of post-mortem lividity is markedly different from the dark pink or dark purple-blue colour normally observed. For example, a cherry-pink coloration is indicative of carbon monoxide poisoning