plant yellowing from transplant to outside! shock?

I have been keeping my plants under 18/6 before transplanting outside to absorb some of this awesome cali sun, but a few of my plants will look like this the next day! Whats going on here! Im using ffof and happy frog mixed, idk wtf is going on! Any ideas?

Did you give them a chance to harden off? Before going from in to out you should let them get used to the sun with small doses of sunlight or even a shaded area for a few days before transplanting into full sun. Good luck.