Seedlings are so fun! I transplanted when they got 3-4 true leaves on them. I potted into 4 inch nursery containers. I just left them out all winter but I'm in zone 7. As for the color they don't change much from seedling to maturity.
They do get much bigger once you plant out in the garden from the 4 inch container. Seems like in just a few weeks. One year I had flats of seedlings.
Can you share some pictures?
