My butternut squash plants, although are growing very well, seem to have this white patterning along the veins of their leaves.
It looks a bit like powdery mildew, however all of the pictures I’ve seen of that online seem to be more spotty and less distributed like this. This patterning is seen across ALL of my squash plants and I’m not sure if I need to do something or just let it grow!
It's referred to as leaf silvering. It's a genetically controlled trait common in the Cucurbita genus. That being said those are a bit extreme.
Take a look at the underside of the leaves. Silverleaf whiteflies could also be the cause.