The earliest sign of maceration is

Degradation: Decomposition causes a loss of anatomic integrity of skin and other tissues such as localized peeling of skin ('skin slippage'), loosening of the skin of hands and feet ('degloving') and loosening of hair and nails. The earliest sign of maceration is skin slippage of the face, back or abdomen which may be seen in 12 h after death in utero. By 24 h, sin is brown or purplish in color. Ref - Krishan Vij textbook of forensic medicine and toxicology 5e pg : 148