If the discharge has a very slight yellow hue, it may not indicate a problem. This is especially likely if the hue only coincides with a change in diet or dietary supplements. However, if your discharge is foamy, itchy, darker shade of yellow, or yellow-green in color, it can be a sign of an sexually transmitted disease (STD) or other infection. Some women may also experience an itching or burning sensation while urinating. The most likely cause is trichomoniasis or gonorrhea and this would necessitate you consult a healthcare practitioner immediately, especially so if the discharge is thick or clumpy and has a foul odor. Also keep in mind that chlamydia can cause a discharge like this, but frequently it has no symptoms at all — so just because you don’t have a discharge doesn’t mean you don’t have an infection.