Grape leaves can look lighter green compared to e.g. apple leaves. Grapes don't need low pH like blueberries. My guess without a picture is your grape is fine. Note that the general recommendation is to not replace any more than 1/3 of the soil in the planting hole with amendments at planting time. However big your hole is the grape will grow out of it soon anyway, they tend to send long roots about 4" deep which can go 10-12' from the plant. I know because I dug up a couple dozen 5-year-old grapes this spring.

Scott

I know other people will disagree with me on this, but when it comes to fruit trees and grapes I say NATIVE SOIL ONLY! and if you must, top dress. Grapes don't respond well to different types of soil = amended soil that roots move through easy and native soil that acts like a barrier when the roots reach it, this can set a plant back as much as three years ( but 1 ~ 2 yr set back is average ) when acclimating to the now denser soil. so I avoid this by just putting it in the dirt where it is going to be planted, no muss no fuss.

Mudflapper, I don't amend my soil for fruit trees/vines and I agree that the best approach is probably no amending. But I don't think it hurts to add a bit, and it may even help weak plants get going in some cases.

Scott