The dark color of semen may be caused by diseases such as seminal vesiculitis or urethritis. 1. Spermatitis is mainly due to the bacteria through the urethra, ejaculatory duct to the seminal vesicles caused by infection. The causative organism is mostly Pseudomonas aureus, and the main manifestations include frequent urination, painful urination, perineal pain, and the color of semen during ejaculation will be red, pink, and so on. General treatment includes the use of sensitive antibiotics such as ofloxacin. 2. Gonococcal urethritis is usually spread through sexual contact. The main manifestations include urethral mucous membrane redness, swelling, itching, urethra can discharge a large amount of purulent secretion and so on. Untimely treatment can cause seminal vesiculitis, which in turn affects the color and quality of sperm. Treatment is mainly based on penicillins, such as ceftriaxone, macrolide, etc. Oral quinolones can also be taken. If the patient has a dark semen color, it is recommended to consult a doctor in time, after clarifying the cause of the disease, under the guidance of the doctor for treatment.