*UPDATE* I chickened out and used Motorcraft Mercon LV the whole way. Dropped the pan, new Motorcraft filter and installed new pan with drain plug. Now on it's second drain & fill. Plan on doing a third and possibly fourth D&F as the fluid that came out was pretty dark.
Mercon LV can and will look darker than other ATFs, even during a short drain and fill
It's a characteristic of the fluid, and is not a cause for concern
It's one thing for ATF to look burnt, if it
smells burnt, that's where the problem starts
SPECIAL SERVICE MESSAGES
21138 AUTO TRANS - MERCON LV FLUID COLOR
SOME 2008-2010 VEHICLES, EQUIPPED WITH AUTOMATIC TRANSMISSION FACTORY FILLED WITH MERCON LV FLUID (PART # XT-10-QLV), MAY EXHIBIT DARK COLORED TRANS FLUID THAT MAY LOOK BURNT IN APPEARANCE. THIS IS A NORMAL
CHARACTERISTIC OF THIS FLUID AND WILL NOT AFFECT TRANSMISSION FUNCTION OR DURABILITY. THE MERCON LV FLUID IS A DEEP RED COLOR, COMPARED TO CONVENTIONAL MERCON V BRIGHT RED FLUID, AND THE COLOR NATURALLY DARKENS AT RELATIVELY LOW MILEAGE. IN SOME CASES, THE FLUID MAY APPEAR TO HAVE A GREEN TINT DUE TO DYE USED TO CHECK FOR LEAKS AT THE ASSEMBLY PLANT. TRANS FLUID COLOR SHOULD NOT BE USED AS SOLE INDICATOR FOR TRANSMISSION REPAIRS.
REFER TO THE CORRECT VEHICLE AND MODEL YEAR WORKSHOP MANUAL AND/OR MAINTENANCE GUIDE FOR DIAGNOSTICS,
REPAIRS, AND/OR SCHEDULED MAINTENANCE.