What would indicate that a corpse had been dead between 2-8 hours?

Hey there! :)

When pressing a corpse, the colour disappears, this is called Livor Mortis.
The discolouration when thumbed upon a dead body indicates the death of between 2 - 8 hours as it is permanent 
This happens during post-mortem 

1. aspect is nothing really because the answer is right in front of your face

Molecules called lipids have long hydrocarbon chains that determine the way they act. they can be fats, oils, or hormones, and even exist in our cell membranes