I have red water leaking/dripping from the vent bathroom fan in the second floor bathrooms. This only happens after a good snowfall and during the snow melt as it warms. We get about 6 hours of dripping and are getting 2 cups of it. What can we do? The attic and vents to the attic roof seem to be sound. Could it be from the vent cap and why is it reddish/pink in colour?