Winn Dixie Mixing brown hamburger with fresh hamburger. Nice and red on the outside, brown in the middle. Yuck! Hollywood, Florida

That the red color in your hamburger is not natural. They use adulterants in your meat to make it appear red, such as carbon monoxide. The brown color in the middle of your meat is meat that was not exposed to this. there's nothing wrong with brown/grey hamburger meat. You are implying that they are mixing out of date meat back in their product and reselling it, can you offer any proof that they are doing so? This would be a major health violation. If you suspect them actually doing this, you should contact your local health department and perhaps the local USDA office.

"Why is pre-packaged ground beef red on the outside and sometimes dull, grayish-brown inside?
Oxygen from the air reacts with meat pigments to form a bright red color which is usually seen on the surface of meat purchased in the supermarket. The pigment responsible for the red color in meat is oxymyoglobin, a substance found in all warm-blooded animals. Fresh cut meat is purplish in color. The interior of the meat may be grayish brown due to lack of oxygen; however, if all the meat in the package has turned gray or brown, it may be beginning to spoil.
"

http://www.fsis.usda.gov/factsheets/Ground_Beef_and_Food_Safety/index.asp#18

http://wiki.answers.com/Q/Is_your_raw_hamburger_meat_bad_if_it_is_brown_before_the_expiration_date
http://www.fsis.usda.gov/Factsheets/Beef_from_Farm_to_Table/index.asp#14