My seedlings are doing very good. I usually do time lapse video recording of my seedlings. Before the seedlings were not much active, they looked like natural dormancy, now they are very active and growing faster. However the color are not yet change, still pale but the leaves are getting bigger.
I have been looking for more information about pale leaves on the net. I found something very interesting:
A chili plant's water needs change throughout the growth and fruiting cycles. Closely monitor the soil to keep it moist without flooding it. Soggy or dry soil will cause the pepper plant to be pale droop."
Here is the link:
The soil are not soggy and the leavers are not pale drooping but fresh pale leaves. So probable the problem may be due to the lack of water and nutrients.