My yellow courgette plant has developed yellow leaves. Is this normal?
The leaves start off green, but then get a few small yellow patches, which eventually spread until the leaf is almost all yellow. It looks (to my untrained eye) rather a lot like cucumber mosaic virus (or at least the picture in my "veg expert" book).
Otherwise the plant is thriving. It's the biggest, strongest of all of them!
Some yellow courgetttes have "yellow" leaves... if the plant is healthy don't worry about it. Some older leaves will pale and die going through yellow, but I'm sure you knew that. :-*
I grow yellow Parador courgettes - the leaves are naturally variegated (Is that the word?) They are paler than the others with patchy colours on the leaves. And yes, courgette leaves gradually die off as it goes along, the lowest ones first.
I would say that the healthiness of the fruits and flowers is a good indication!
Both my Parador and Soleil courgettes have yellow fruits and a yellowish tinge to the veins of the leaves, it's normal for them so don't worry! ;D