BTW...does regular DOT 4 brake fluid turn from it's light amber color to a dark murky color as it absorbs moisture? Or does the darkened fluid occur for other reasons? Obviously if you're using a colored brake fluid (like blue)...this color identification won't apply.
Just some FYI to add to the discussion...especially those that were unaware of the hygroscopic nature of brake fluid and why BMW has the 2 yr recommendation to flush:
(from owners manual)
(from BMW TIS)
