“…It is reported, however, that the appearance of peritoneal endometriosis can vary considerably, ranging from colorless blebs (non-pigmented subtle endometriosis), to hypervascularized areas and the classically described black and powder-burned lesions (pigmented endometriosis) [17,18]. During histology, the subtle lesions may appear to be normal peritoneum, illustrating the potential difficulty in identifying them correctly [2,17,19]. The revised American Society of Reproductive Medicine classification categorizes the lesions as red (red, red-pink, and clear lesions), white (white, yellow-brown, and peritoneal defects), and black (black and blue lesions) [20].…”