Try a stain pen.

Here is a link that might be useful: something like this

There's a heat/steam method to raise the grain on wood dents. Not sure if that applies here. Try googling. Test inconspicuous spot or sample board first.

A technician with a few shellac sticks and the heat tool that is used to melt it can do a remarkable job disguising the damage. Furniture repair technicians use the same tools and media in their repair work.