Serosanguinous drainage is slightly yellow or colorless in appearance. It's also thin and watery, causing bandages to become wet without leaving a stain of color. In some cases, the drainage is slightly pink, which is caused by a mixture of blood and serum from the wound.
Serosanguinous drainage, also called serous exudate, is normal in small amounts during the early stages of the healing process. The drainage typically occurs during the first 48 to 72 hours after an incision is made. Serosanguinous fluid can also weep from the skin when there is no incision. A large amount of fluid is serious and should be reported to the doctor immediately.