Usually, even if the liquid is colored yellow, greenish, gray, or brown instead of being purely clear or white, the liquid is “actually
milk” that can be of any consistency that has been made by the
breast.
Breast discharge can be caused by a wide range of disorders,most are not worrisome, but if you are having this problem,I would suggest seeing your doctor and ask for some type of tests,particularly if the discharge is unilateral.