Day 21 new leaves look kinda pale and yellow, whyy...

# 1 issue with seedlings is keeping them too moist/wet notice the down turned leaves. Secondary issue is the red stems/yellow leaves looks a like a lack of nitrogen that can be caused by an over watering or soil that stays too wet for too long. This doesn't mean give them more nitrogen their roots can't absorb it because the soils too wet. Let them dry out a bit before the next watering. If they look like they have improved and there are no nutrients in the starter mix use 1/4 strength nutrients on them not drowning them with moisture.The soil looks like it has a lot of vermiculite in it which holds a lot of moisture pretty common in seed starter mix. . If/when you re-pot them be sure to add extra perlite to your mix to allow for more oxygen to reach the roots and allow for faster drainage. Hope this helps👍