Worm bin question

[asterroc]

To anyone else with a worm bin, I've a question. I went to harvest some soil from it (I was repotting plants), and I noticed the soil was very gray, and not the rich brown I was expecting and had seen in the past. What causes this, and is it still good to use? My best guess is that I've been low on the "green" content lately (as in fresh veggies), and high on the paper pulp. There were LOTS of worms, at least one in every spoonful, so it's not a shortage of digestion.

x-posted