Endometriosis lesions can indeed present visually as white (along with other colors such as red and black) during surgical inspection.
The claim is a specific, falsifiable empirical statement regarding the visual characteristics of endometriosis lesions. Retrieved papers (specifically papers 6 and 7) explicitly document white peritoneal and superficial endometriosis lesions as part of standard visual classification schemas during laparoscopic assessment. Therefore, the claim is supported by the literature.