My urethra opening looks white inside checked for stds came back negative?

See a urologist.: Diagnosis of a skin lesion such as this requires a detailed history and physical examination. White colored abnormalities of the skin of the penis can be a skin pigment condition like vitiligo, or if it involves the lining of the urethra, a condition called lichen sclerosis et atrophicus. Please see a urologist who can help you come to a diagnosis & treatment plan where needed.