If I see it correctly, the cotlyledons are yellow, or getting there. The first set of leaves looks like it's tips are yellowing. When the coyys turn yellow it's time to feed. The plant takes from those first, which is why most growers say don't feed for a few weeks.
Since the lower leaves are starting to turn yellow as well, it's a sign it's past hungry and is starting to starve. But your pots are small now too, and I'm guessing you are getting some root bound which makes the plant take whatever food is available really quick. I'm guessing you are watering more often now than a week ago.