leaves loosing color

I recently transplanted from a solo cup to a half gallon and a day after I noticed that the first actual/true leaves turned yellow and died and the ones above are starting to lose their color. If I just transplanted into new soil would it be okay or should I add in some 9-3-6 Dyna Grow? I'm sure it's a nitro Defiency but if it is wouldn't transplanting give it nutrients? And if so should I still continue to feed it? I gave it 1 ML a while back and the new leaves are looking green but it's the leaves bellow that are losing their color. Any tips or thoughts?

Depends on the soil you transplanted into. A good quality soil would provide all the basic nutrients needed for several weeks. A seedling soil would starve the plant and need mutes. Looks hungry to me.

start over that plant is stressed out and will be a runt if it doesn't die. next time make sure you have good soil you have something going on with the soil and the plant doesn't like it that plant should be green and healthy.

are you PH,ing your water, is the plant outside

I am PH,ing the water. It's indoors and the soil is Dr Earth Pot of Gold.