Veins in the leaves are discoloring Big Bud Auto 7 weeks old grow in soil

There is some burning on the tip of some of the leaves, but there is a clear purple hue in some of the sugar leaves. Looks more like a phenotype for me, I would suggest dialing back on the amount of nutrients you are adding and see how that works, but the leaf veins and margins look healthy, except for of course, the bits of burning on some of the tips. As for the burning, its a sign of excess, you are likely using too much of something. As I mentioned, just feed the plant water for 3 weeks and let the nutrients in the soil already do its thing, see how that works out.