Hi Rick and welcome to the forum.
A straight razor blade will take everything down flush to the hull. For scuffs I use 600 Wet/Dry, applied wet, followed by auto rubbing compound. This brings it back to a nice sheen, but not the original shine. There are smoother auto and plastic compounds that can polish it up even more if you want. For deeper scrapes you probably want to start out with more agressive paper then work it down. In any event I prefer the wet dry as it doesn't seem to clog.
There is no color change. If you want a little more gloss and richer color, try the Hobie Protectant or 303 Protectant. They dress up the boat nicely and last for a few outings. Between the two, in a side by side test I found that the Hobie product holds up a little better. Just be careful where you put it as it makes the surface slippery!
