PH Fluctuation Early Signs?

Plants look fine! New leaves will always be a bit paler at the beginning... that's natural! Don't worry about the discoloration at this stage!! The first leaves are pretty much always a bit funky. You may have stressed them out, though by feeding them a little too early! With my autos (which is all I grow), I leave them alone until they're about 1-1/2 to 2 weeks old and then start them off with 1/4 of the nutes. The next time I feed, I bump that to 1/2 strength and then full strength. Definitely add some microbes to that first feeding as they help the root structure become large and strong and they also help prevent lockout. As always, alternate feeding and watering... and always wait until they're bone dry. They're named AUTOflowers for a reason... they're pretty much going to do what they're going to do and as long as you ensure the ph of your soil is within range, they'll turn out just fine. Both your temp and humidity look good... good luck with your grow and relax! Enjoy the journey!