I have a few seedlings which are maybe a week and a half to two weeks old. Their stems are dark, kinda purpulish reddish. I have another one which just sprouted a day and a half ago and grew really quickly. It's stem is actually green and it looks really nice. Am I overwatering the older ones? Does stem color mean anything? Also, to make note of, the oldest one is actually growing the slowest. It's cotelydons (?? whatever the two leaves that grow first are called) were damaged when the shell of the seed got stuck to them and wouldn't come off. I had to pick it off and now the edges of both leaves are yellow. I'm guessing it's going to die because it is growing so slowly in comparison to the others.