yellow leaves

hi guys just wondering if sum1 can tell me what is wrong with my baby, i recenty purchaced 5 x lsd seeds from barnys farm seeds, i lost 4 of them from over waterin and burning them i have 1 left and got it under a 400w hps the room temp is at 27.c and there,s lots of fresh air the problem is that the new leave,s cumin through are constanty yellow are they suppossed 2 b like this will they turn green? any help appreceited

where pic ? no pic no answer..

i cant put any pics up as i havnt got wire 4 camera, my plant is growing, but not sure if new leaves start off yellow and then turn green? could sum1 tell me if they meant 2 b like that please? thanks