Some water damage still visible after sanding

[Garald]

A couple of months ago, I stupidly left the roof windows open in part of the attic (I had used some silicone sealant that smelled to high heaven) and forgot about it when I went to sleep. Guess what - rain, water damage. Several warped boards, lots of staining at the end of boards.

 

My hardwood guy sanded the floor (put me back some 1700eur) and refinished it. Now it's all perfectly flat (in fact, flatter than before - the floor had been laid by a general contractor) but there's still some staining visible at the ends of about 10 boards. Girlfriend not happy. Hardwood guy says he can replace the boards for about 1000eur, but that there are better uses for my money, in the house or elsewhere.

 

Is there a less pricey cosmetic treatment, possibly DIY? Note: I think the stains have become a little less eye-catching in the two weeks since the sanding, but it may just be my sunny outlook on life. Note 2: the finishing is acrylic, I think.

PS. The photos don't show a sample of damage, but the total remaining damage - the rest of the floor is fine.