Hamburger meat is still good even if it has turned brown.
As long as the hamburger meat does not smell bad or the hamburger meat is not slimy in texture and feeling then the hamburger meat is still safe to eat.
If the hamburger meat has been frozen and it turned brown it's still safe to eat and is still good to eat.
Hamburger meat can last a year or longer in the freezer before it goes bad but the taste may change as well as the color the longer the hamburger meat is in the freezer.
Hamburger meat only lasts around 3 to 4 days in the refrigerator but the freezers freezing temps keeps bacteria from growing on the hamburger so the hamburger can last longer frozen.
Just smell the hamburger meat and if the hamburger meat does smell bad then throw it out to avoid getting sick.
But if the hamburger meat still smells good then it's okay to eat even if the hamburger meat is brown.