I understand that 'pure' liquid Methane is colorless', odorless,
and superficially resembles water, if you don't try to takes it temperature.

But....With organic impurities dissolved, or floating in it, it may take on a dark color.
I wonder if planetologists have given serious thought to the idea that
a body of liquid Methane can have all sorts of gunk floating in it, so it would tend to resemble a lake full of dark porridge than a pool of clear liquid?

Jacob

"The liberty to air speculation and opinion are democracy's gift to you! - Fight to defend those gifts against all naysayers!"

ANON