Dark Grayish Chunkies

I have to say, I've never seen this before - or at least never noticed it. We've got a starter of Westmalle yeast going. It's on the stir plate and we're using the oxygenator thingy Bade made (see the Wiki). Anyway, this morning there are chunkies spinning in the mixture. Fairly small, but still chunkies, that appear to be sort of dark grayish in color. Haven't tasted the starter because it's still actively going. We'll crash and check it before we put it in the beer. Has anyone had chunkies in their starter before that look like this? I can't think there would be an infection issue. Our sanitation is usually pretty good and the air for the oxygenator is running through a filter. Am I being paranoid? Thoughts oh wise fellow brewers.