Yellowing leaves

I have some SSH that have completed the 7th week of flower. Looking nice. However my fan leaves on one of the plants I am flowering has started to turn yellow. I hit them with some Tiger bloom today for the N, just to be on the safe side. This may be a variety that the fan leaves at a certain point in flowering do turn yellow. I don't know.

I am also flowering another strain of SSH that isn't acting this way. Since it was below 50 degrees while outside it turned purple in the stems and flowers. No yellowing of leaves.

Any one else seen this? Should I hack off the fans leaves now in 8th week of flower?

Fading lower leaves in mid-to-late flowering is natural and nothing to worry about.
Don't cut them off unless they shrivel up. Some will actually fall off on their own.

Just go with it.

If upper leaves yellow, then I do remove them to get the light to good leaves below, if leaves that have their stem starting within a bud, I remove them, but if they are already shaded, and they don't present a risk of generating bud rot, then I leave the plant to feed on the goodies stored in those leaves.