Depends on what color the gelcoat is. I have a 20' RED 1986 runabout. I noticed a chip in the vertical "transition"... (on the edge) from the transom to the side of the boat. Outside
Corners are particularly sensitive to chipping.
I found a small bottle of paint at a local Hobby Shop that matched the hull color and "filled it in" ..in layers...drying in between layers... with the paint using an artists brush. The colors available at the Hobby Shop are almost infinite. It's a "mask" on the edge and not so noticeable. .
Amateurs will NOT get it right trying to match gelcoat colors with a gelcoat repair kit....Just the way it is..
NB
EDIT: The paint I used was
Badger Precice Design Model Flex...Water Based Acrylic