Out on the slopes
Hiking up Mt. Hancock off Kancamangus gives you the best of both worlds. The viewing areas are small so it's not an extremely busy trail. There are some small fish in the river and a mini flume on the south side that should be kicking. Both peaks have some short steep sections. Parking on the Kanc could be tough.I was hiking in southern New Hampshire this past weekend and the foliage was juuussstttt starting. Basically made me think that Columbus Day weekend -- the "usual" high tide in the White Mountain region -- is going to be high tide again.
A lot of people go for the soaring above tree line views -- i.e., the Franconia Ridge traverse, Mt. Washington, etc. I've done that, but in my experience, you're so high above the colors that the experience is muted until you get back down into the trees. One of my most enjoyable foliage hikes was just a long walk along the river.