Some shops give you a "touch up" kit after they awlgrip the boat. If
you're lucky, you have it. If your still lucky, you know what color
awlgrip was used on the boat, and youc an get some awlgrip and match it
up. (Go to a yard/paint shop and ask them--you dont' really want to
deal with even the quart-size containers.)

That said, it's very difficult to touch up awlgrip and not leave a
visible seam. Since it's paint, it goes on in layers, and the new
layer sits higher than the old layer. You can't buff it, so what do
you do? You can try feathering a little and use a light hand. I
wouldn't tape around the patch area--that will just leave distinct
lines where the tape was. That said, be mindful of drips.