ha- sorry: it was brewed a couple of years ago, but I don't still have it. It turned black after a couple of days and I dumped it after a couple of weeks when it didn't look any better. The other half of the same batch (the one that my friend took with him) did not turn this black color, which is what makes me think it's environmental.
The current beer is still just as dark, even when looking at a sample. It looks like a stout, not a pale ale. I don't think it's the yeast dropping out.