    The warning label on each coconut describes how to treat the water within each. The water on the brown coconut is to be discarded; the water on the white coconut is safe for consumption.   In what ways is the water from the brown coconut different than that of the white coconut? 
I have been in the coconut export business for over 6 years. Coconuts are either 'young' 7-9 months or 'mature' 11-12 months old at the time of harvest. If you want sweet water, the coconut is harvest young, when the sugar content and volume of water are at their peak.   As the coconut ages, the water is absorbed as the 'meat' in the coconut grows thicker. The water also looses its sugar content. After husking, young coconut shells are white and quickly turn brown UNLESS treated in chemicals to keep them white for an extended period.. The water in an older, browner, coconuts is still safe to drink, just not as sweet.   If the water is rancid, so is the coconut meat. 