It's got Varnish on it so the stain is sealed in, nothing you can do about.
The real fix is to sand it off and start over, and do it right.
However, It's clear to me from the pictures that there wasn't enough coats put on to begin with.
So since plan #A would be sand it off and start over, you may as well punt and see if a quick fix helps.
The Helmsman will darken alittle with every coat. And it will make the front look "Better". Not much
is going to help the back I'm afraid. But I would bet two nice consistent coats spayed on properly will
improve the front a great deal.
It is not spray paint, do not use it like spray paint or you may as well save you're money. Spray with complete
strokes from top to bottom, and back again. Do it in 4" stripes only stopping the spray when you reach the ends of the target.
Every place you stop the spray will show, if you are inconsistent.
"Error of opinion may be tolerated where reason is left free to combat it"