REX and Real weather

I'm not registered on the REX fourm site yet so I'll post this here. After a week of trying to pick the perfect components of REX I've almost completed the task. I'll later post my favorite picks. When starting a flight , say from KLAX, I do NOT, repeat, NOT get the CORRECT weather (winds, cloud amounts/types, barometer etc) until I also start Active Sky 6.5. Then all of the REAL weather loads correctly. Why do I have to also start and use AS 6.5 to get the correct Real Weather when using REX? Other than that I'm really loving REX ! One last question. I've lived near the Red River in Louisiana and it has been BLUE for the last 10 years in Flight Simulators. REX has a choice of BROWN Inland Waters but I can not find any "waters" that are brown. Is there a way to make my Inland Red River BROWN with REX? Thanks jerrycwo4