What Leads To Redness In Body After Death?

hello dr,my mom was suffering from cancer for the last five years but things were under control as she regularly used to get her check up done.then in the last week of jan 15 she had severe pain in stomach mucus and blood used to pass. she was hospitalized in one of the best hospitals of delhi.and she passed away on march 18.After that her body color changed to red . what was the reason for the change of color?i wolud be highly thankful to u fr a prompt reply.