Should i be concerned or is this normal?

This question hasprobably been asked befgore but every search i do just brings up a load of threads with a few words highlighted, so here goes . . . I've just pulled my girl out of a 24 hour darkness period as suggested to put her into the flowering cycle, gave her a bit of a misting and powered up the hps , and noticed all the smaller leaves are a sort of light green / yellowy type of colour, is this due to the lack of light stopping photosynthesis, or is it something else i should be looking into?? also i took a couple of cuttings from her lower branches, but I haven't read anywhere of this causing yellowing of the leaves , any help would be appreciated and the sooner the better as she was in full health before the lights out . . cheers in advance , WoW

24h darkness is not enough to make the leaves yellow from lack of light. Yellow leaves can be a symptom of so many things, without pictures it's impossible to tell. Nitrogen deficiency and overwatering are 2 of many reasons.

Panic over It was only the small shoots that were yellowing and now she's looking green all over, possibly the flora nutes 1/8 strength i poured on her snapped her out of it or it was lack of light , either way I'm all panic free now . . .. these girls know how to scare you dont they . . . . . cheers for the treply tho , its a rare thing sometimes round these parts . . .