this is normal. just pick off the dying leaves the best you can, when you have dying leaves esp. during flowering, these leaves could land on a bud site and could later become a problem like mold.
so do not stress, everything is normal. when the plants go in to flower they use energy from those leaves, and in turn as the plant gets closer to harvest more leaves will die and turn yello. you will also get some fades with different colors at times esp. towards the end of the plants cycle and the closer you get to harvest. it is the plants way of producing those buds we are all after. enjoy your harvest you will be happy i am sure of the outcome