The damaged ones are the 2nd leaves correct? I'd give it some time to grow a few more sets of leaves before I'd worry too much. They look okay, the one in the third photo looks a little light but it's pretty early to tell for sure if it needs anything. As long as your PH is good and your soil isn't too hot it should be fine. If they continue to lighten up you could try a foliar feed of magnesium and it may help.