How do you know if you're getting gangrene?

Tissue turns: Black. Nonvacularized tissue dies and turns black.

Usually obvious: Gangrene means dead tissue. When infected it is called wet gangrene because the pus makes it wet and smelly. This is an absolute emergency and these people ae usually deathly sick. Dry gangrene is not infected but still should be seen right away because it usually means something needs to be fixed and because it can progress quickly to becoming infected. Both are usually black or gray in color?