Semen is normally a whitish-gray color. Changes in semen color might be temporary and harmless or a sign of an underlying condition that requires further evaluation.

Possible causes, by color, include:

• Red semen. This could be caused by inflammation of the prostate or the glands that help produce semen. While red semen can be alarming, the cause is usually harmless (benign), especially in younger men.
• Yellow or green semen. This could be caused by an infection, jaundice, or the presence of vitamins or medication in the semen.

If semen discoloration is a new sign and it continues for more than a week, talk to your doctor or see a urologist.