But to answer your question. It really depends on how big/deep the cut is. If its small, doesnt require stitches, & you butterfly it good for a couple days, it should leave little to no scar. Probably will not need touching up.
If its a gaping cut that wont close up and seal on its own it will leave a noticable scar. Some scars can be touched up but the color is almost never exactly the same in a scar as it is in the surrounding skin.
My tattoo artist refuses to tatt over a large surgical scar i have on my leg. He said it most likely will run under the skin and look blurred and faded. Not to mention the extreme nerve pain it would cause, meaning i probably couldnt sit still or prevent my leg from jumping around lol!