One plant has a yellow tinge

Hey ya'll, here is a quick overview. My two plants are 3 weeks old from germination. They have been indoor grown for 2 1/2 weeks 24/7 light schedule. I had to move them outside. They are still in their pots and I recently have been feeding them 5-5-5 water soluble plant food. One has been growing great and mind you has been growing strong since germination. The other one is a half a step behind but still strong. This morning the whole plant has a slight tinge of yellow in the color. Is it because of too much fert? please help!
Specs:
All organic soil with 14-14-14 plant food that I mixed in.
recently using 5-5-5 water soluble plant food.
Watering once a day

sounds like ur pH is too low so the nitrogen is being locked out. keep the pH between 6.5 and 7.0. since its too acidic add some dolomite to the soil.

nute burn usually shows in spots here n there. i think hes right bro, not enough nitrogen if its the whole plant