If you are not staining,just clear coating raw(sanded) wood,you can re-sand and recoat the areas with dark streaks.

I see one+ boards that either took more stain or were darker before staining. Two boards to the right of the dark one is a half and half light/dark board. Seems to me the center of the floor is made of darker boards. Not unusual, but not optimum placement. It is sometimes difficult to look at raw wood and tell how stain will be absorbed.

Not the dark board but those arcing streaks where it looks like something very heavy was dragged across the floor.

Needs more sanding.

Are you going to use a rug? If it is under the rug, you won't see it. Even if you don't, furniture will probably cover most if not all.

Then it's live with it, cover with an area rug or furniture. Call 'em character marks. Upside it that when you cause a boo-boo to the newly finished floors, you won't be so upset with yourself. :-)