Looks like you could've used your veg nute a week or two longer, but doesn't look too bad. If you want to slow the yellowing, add a little veg nute to your next feeding, perhaps mixing it 'half n half' with your bloom nute, instead of using just bloom nute. Then go back to your bloom nute, because now would be a bad time to get carried away with the nitrogen. Too much, and it'll delay harvest, and cause them to 'reveg' somewhat, growing new foliage, instead of putting their energy into bud development.