This is typical “Legacy” agreement M.O. to protect family. Likely lethal injection. The pink may actually be related to the crime which I will not discuss at this time. Also could be the public “cover” of cancer. Her best friends had no idea she had cancer because she did not.

https://www.yahoo.com/entertainment/kelly-preston-death-certificate-died-home-amid-breast-cancer-battle-report-171640908.html