Vision: Dreaming that your clothes are stained: take a close look at your habits and behaviors—the impression you make on others is very negative. Grease stains on your clothes: a marriage might make you prosperous. Soiling your clothes: you are about to make a mistake. See Fat.
Depth Psychology: Stains are often signs of a bad conscience, feelings of guilt, or too casual an attitude toward life. Which is it in your case?... Dreamers Dictionary
Dreams of a stain signify unhealed wounds, lingering trauma, and your fear of being found out for being less than perfect. Your dream is giving you the message to make amends for past transgressions and forgive those who have hurt you, including yourself. Also, keep in mind that there is a part of you that has never been hurt, harmed or damaged. See Scar and Spot.... Strangest Dream Explanations
Dark spots in the soul, being soiled and feeling guilty. Often combined with being embarrassed. There are also “erotic” spots, which, however, appear seldom. Usually it is a suggestion to become aware of a “dark spot.”... Little Giant Encyclopedia
If the body is seen stained with blood, dung, excreta and all that issues from the body, it symbolises unlawful wealth owned by him or it means he will receive haraam wealth in the future.... Islamic Dream Interpretation