Hello and welcome to the forum. Thanks for your question. Always know that checking in with your doctor is a valid and welcome response to a health concern. Semen can change colors. Most often, unless it is accompanied by other symptoms, it is nothing to worry about and you give it a few days to see if it resolves. The greenish color could be due, however, to prostatitis most likely if it persists. https://www.healthline.com/health/mens-health/semen-color-chart#quick-chart Do you have any other symptoms?