Still thinking whether I should get 5D Mark 3 or Nikon D800

Do you have troubles with colors of D800 in JPEG or in raw either? Why can't you corect them in LR? You can make a camera profile and apply it to all your photos. In Dpreview test scene D800 and 5DIII do have different reds in JPEG, but two color charts are indistinguishable in raw.