Tomato seedlings turned purple
Hello I planted my Roma's back on March 30th. I didn't use any lighting other then what sun light was coming through my window. They were started in small cells. I up potted them twice since. They are now in 16oz cups. They started to turn purple the first time they were up potted. I have down loaded a pic. As you can see they haven't grown much either. Will they survive and what can I do?