Cotyledon popped yellow

I had worse, all is fine, relax and good luck growdiaries.com/diaries/207878-dutch-passion-auto-skywalker-haze-grow-journal-by-einamio/week/1173352

depends. it could be something irrelevant that never progresses or something that continues to go downhill. you need to know the rate of change which a picture does not communicate. too much light, improbper pH, hot soil etc... if something like that is the cause of it, you need to react sooner than later. Do be certain. It's always easier to give than take improper excess away - i.e. don't compound the problem with a new one that might be worse, lol. So, wait and see. if it gets worse, you'll want to do someething. in meantime you can do some simple things like test pH or re-assess any fertilization. if this is a soil with a pre-charge, you shouldn't be fertilizing, yet, for example. if nodes never develop any stem between them, it could be too much light. can't tell yet, but in coming days such a thing would be obvious. leaves will look like they all originate from 1 spot -- at this early stage that's kinda normal, but should see some gap form between them as they develop more. Your plant looks fine relative to age in this regard. if those first serated leaves stay tight and next node stays super tight too, then you know you need to back off the light a bit. and the opposite is even easier to see if it stretches and gets weak.

It happens, nothing to worry about or attempt correcting at this time. Just give her good light, moisture and love! 👍