If it's sealed from air and stored cold in the refrigerator, then the processes that make LME oxidize and darken are reduced to a minimum and will take a very long time to show up. LME stored in this manner will last quite a while. You are definitely fine with the LME you have.
On Deck: Jamil's Vanilla Robust Porter
Fermenting: Orange Blossom Mead
Kegs: Element 56 Pale Ale, Ron's Belgian Blonde, Summer'n Saison, Furloughktoberfest '09, Grateful Pale Ale, Sam Adams Cream Stout Clone, EdWort's Apfelwein