Does the brown color of the discharge affect ritual purity for one who purifies herself with dryness, and is its mixing with menstruation the cause of its brown color?

Brown discharge after menstruation, known as "kudra," is considered part of the menses if it connects with the blood. However, if a woman ascertains that it is coming from the urinary tract, and that it is not kudra but rather "wadi" (vaginal discharge that is not blood), then it does not affect her state of ritual purity.