This was my first reaction, although it may not be so obviously a right choice if we want to balance it with the rest of the sentence. But something to start us off anyway.

Aguas turbias... voces claras = Murky waters... clear voices

Results 1 - 10 of about 270,000 for "murky waters".

Murky waters - Idiom Definition - UsingEnglish.comMurky waters - English Idiom Definition. ... Where people are behaving in morally and ethically questionable ways, they are in murky waters. ...
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Part of a very old phrase "pour oil on troubled waters" that repeats over time. Some references are: 'Troubled' has been used to mean agitated and disturbed, either of mind or in reference to physical elements like water or sky, since at least the 14th century. In their use of the singular 'water', rather than 'waters', as the title of their 1970 album and single Bridge over Troubled Water, Simon and Garfunkel harked back to the original usage. We now more commonly say 'troubled waters' but earlier references stick to the singular 'troubled water'. For example, J. Walker in A true report of the disputation or rather priuate conference had in the Tower of London, with Ed. Campion Iesuite, 1581:

"Ffiij, It is troubled water when we mingle our workes and righteousnes with Gods."

Even earlier than that we can find references to 'troubled sea/flood' etc, as in John Wyclif's translation of the Bible, 1388:

"The troblid flood that moistith Egipt."

The use of 'waters', as opposed to 'water', began in the late 18th century. For example, this piece from Benjamin Rush's Essays, literary, moral and philosophical, 1798:

"His presence and advice, like oil upon troubled waters, have composed the contending waves of faction."
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