WOW, another believer in Ammonia!
If you want to green up a plant real quick, ammonia. The best thing to green and perk them up immediately is to foliar feed with ammonia. Super diluted. Put about a shot glass full in a standard lil mist bottle. It is a trick I learned many years ago for killing powdery mildew on sun leaves. (You will never go back to milk or baking soda for PM problems. I noticed all my plants looked 3 shades greener the same day. It foliar feeds them nitrogen ( NH4+ reduces to NO3-) and they absorb it incredibly great that way. Especially clones trying to sprout more roots.
Here are the rules though:
Never mist them with ammonia in the sun outside or under high discharge light indoors. Mornings or evenings where there is no direct sun. They will burn ( just like neem oil or horticultural soap or spinosad). For Clones, mist clones 2-3 times a day when needed under CLONE lights only. If you have strong lights on your clones dim them, raise them more, or just do it before or after on cycle.
Make sure the leaves have dried before you mist them again the same day. I usually do 3 mists per day while needed.
Minimize or kill fans for a couple hours. Ammonia reduces to nitrate in solution slower than it evaporates off as a gas. It would rather become a gas then reduce to nitrate while on the leaves in solution. It will evaporate away too fast under strong air flow and not be effective.
Only use on vegetative plants. Once they stack calyxes in bloom you don’t want to get ammonia on the buds. They don’t want nitrogen blast while blooming. It can slow flowering times by then.