The yellow color or "ambering" is not related to the stain color. From all I've read it is a result of an oil based finish. I did read one interesting blog recently that suggested first applying an oil based finish and then applying a water based finish. This goes against everything I know about finishes (my father was involved in formulating finishes of all types his entire career). The blogger claimed it was done in her house. That said, my oak floors are a medium brown stain with an oil finish. After 12-13 years I don't really see any ambering. I think by the time you begin to notice it, it will be time to refinish the floors anyway. Here is a link that might be useful: Why hardwood floors change color.

I just had Bruce floors put in and these were 2 of the 3 colors I was looking at. The other was Saddle, which is what I ultimately went with. If there had been a color that was a 50/50 mix of Saddle and Fawn I would have gone with that one, but Fawn was too light for me. Gunstock is redder, and is red oak while Fawn is white oak and IMO more of a 'neutral' brown. Fawn might be a tad bit lighter than Gunstock - it was lighter on the sample board I had but it's hard to tell whether it was the piece of wood vs the stain color in general. Fawn does not seem to be a popular color because I couldn't find any photos of it other than the marketing photos, which all seem to be Photoshopped anyway. There are a number of different photos of Gunstock if you do an image search, though. Really with these 2 colors it's mainly a question of whether you want a more red-toned brown or a yellow-toned brown. With the cabinet and granite colors you have it could go either way, it'd just be a matter of personal preference. In my case red tones would not have gone with any of my decor so I purposely avoided them.

Water bourne urethane is the closest thing you can achieve to resemeble any woods true natural color without any alterations. Staining can still be done to achieve a color you want if the water urethane doesnt work for you colorwise. But since it sounds like you dislike yellow adding the water urethane OVER the stain will help keep true to the original stain color choice. Adding Oil polyurethane can give the color a richer appearance but does also tend to add a bit of a honey tone in the early life of the floor and then tends to amber with age. Water bourne urethane does age and change tone but not nearly as prevalent as oil based polyurethane.

Most people suggest colors in the green family which is nice but I'm a big fan of sunflowers and decided to use a soft yellow instead. We put it in both our kitchen and breakfast area and like it alot! Not only does it give the kitchen and dining area a very warm and cozy feel and it also has a very pretty glow when the sun is shining in! Not to mention it matches our honey oak cabinets perfectly!