yellowing leaves in flowering?

i know that its normal for older fan leaves to start yellowing late in flower, but i noticed that my one plant 4 weeks in is starting to lose pigment in the leaves(a very pale green) im not stressing to much over it, rele just curious, bc i didnt expect this to happen for another 2-3 weeks

you most likely have a nitrogen deficiency

Depending on how many weeks you got left until your harvest...have you already started to flush?