Bud places are too much yellow

I see you asked not once, so its just too quick grow, put them to natural light, sun, and yellow will be light green, just gimmick of light, freshest grow looks a bit yellow,but its just a fluke for your eyes . All is good. Can agree on slowing down N, or just slow down with food, you give a bit too much. All the best !

I think that the problem can be solved by increasing the distance between the light and the seedling. If that doesn't work, increase ec.