Choosing Your Favourite Cut

Myth:
The colour of frozen meat (such as pork, beef and mutton) is usually darker because the meat is not fresh or of an inferior quality.

Fact:
The colour of meat, frozen or not, is affected by the presence or absence of oxygen. Frozen meat in vacuum sealed packaging is darker in colour because oxygen is not present. Vacuum packing prevents meat from becoming rancid and prolongs its shelf-life if meat is kept under proper refrigerated conditions. Once frozen meat is exposed to oxygen in the air, it will return to its original colour.

Source: http://www.ava.gov.sg/FoodSector/FrozenMeatInfo/Common+Myths+About+Frozen+Meat.htm