New growth looks brown

pigmentation.. might get some colorful leaves or it might grow out of it never to be seen again. this is not anything bad. If night time temps are below 68F, that could cause a faint red like this to show up. So, either genetics or temperatures.. neither is a huge concern but should try to stay 68F or above when lights go out. This is same effect that causes fall colors (the cold part). --- Do continue to fertilize as you have. Ceasing will only slow your plant down. Do react to leaf symptoms and adjust, of course. If anything else is going on concurrently to what you ahve pictured here.

Hello my friend, this is because of the nutrients. You do not need to top dress or use other additives for the next 2 weeks. Happy new year my friend and enjoy this grow!

was the soil amended already and how high are your lights up and a full picture of the plant as well would help alot more ...we need to hear more about your environment