If you prevent oxygen from getting to red meat, it will be a browny green colour. That is why when you buy meat from Woolies or Coles and a piece is overlapping another, the bit underneath will not be red. So if you put stuff in cyrovac packs while it is quite young, it will stay that colour and you can still eat it. That is also why 'airing it out' turns it red.
If the roast was cryovacced for the 6 days, then I would eat it. If it is that loose plastic glad wrap stuff on a tray, I wouldn't touch it after that length of time.