Not sure what is causing leaves to go yellowish

Don't worry, it's normal, enjoy the harvest!🙂

This is the plant using up the stored nutrients there isn't anything to be worried about there it's normal also useful information so many people think flushing is a myth I have met growers with 20+ years who also claim this as a myth when curing it will break down whatever is in there anyway I use to flush now just give it a few waterings at the end I usually find when they start to take the nutrients from one leaf it tends to take more than one leaf after that.

Si es la semana 7 de floracion. La planta esta consumiendo sus reservas de nutrientes es normal que algunas hojas cambien su color. Sigue con lo que tiebes planeado. Saludos

No diary = no information. Could be a couple of things - natural fade, deficiency of phosphorus.. but can't tell you because you haven't told US anything about your grow... don't even know what it is you're growing! Good luck...

First photo has 2 leaves from the same plant the darker one comes from below the canopy level ( older leave ) the weird one comes from the top of the canopy, very close to the light