Topic: Why are my peppers and tomato seedlings going yellow?

[Two Choices]

For some reason my veggie seedlings are all looking a bit yellow and some peppers have brown marks on the leaves. Used same seeds and compost as always and they are in the greenhouse on a heated bed (on at night but off during the day). Any suggestions and remedies welcome  ???

[dtw]

It's been quite cold at night over the past few days, do you have a cover on them.
The roots might be warm, but the leaves will be cold if not.
I'm no expert, so it might be worth adding a photo if you can.

[sunloving]

I'd give them a feed in the next water to see if that picks them up. Yellowing is often a nitrogen or iron deficiency if it isnt a cold thing as above.
 X sunloving