The oil based polyurethane is most likely causing the color shift. Or, you could have what is called stain bleedback, where some pigment that seeped into the cell structure of the wood is being forced back out and into the polyurethane.

I once stained a staircase, balusters and railings and it all looked great. However, when I returned to the customer's house the next morning to apply the finish materials, all of it had turned pumpkin orange. It was a lot of work to get the stain off and I never did find out why the stain decided to do a color shift.

BTW, white oak floors look great with just a natural stain and then coated with a quality commercial waterborne polyurethane. But, there are other finish materials and methods you may want to consider.

Good luck with your floor.

Hi there. We have just had our floors stained and finished and had the same problem. After the stain (Minwax Dark Walnut on Red Oak floors) sealer and one coat of water based polyurethane, we loved the color and was still relatively dark. However after the final coat of oil based polyurethane, the floors have gone very amber, not at all what we were hoping for!

How did you fix yours? Any advice would be appreciated as it seems like our only option now is to resand and reapply a water based poly?!

Same thing happened to mine that were stained Dark Walnut. I loved the dark walnut color, but after two coats of oil based polyurethane, they are showing some orange to them. I have white oak floors stained dark walnut. They should not be showing any sign of orange. I do not like the oil based polyurethane, but it's too late now. So many contractors use it. I didn't know any better to tell them to use water based instead. I miss the neutral coolness of the dark walnut on the white oak. Orange. yuck.

Anyone know a way to fix it besides starting over with sanding and refinishing again using water based poly?

The "orange" is the OIL BASED polyurethane. Yep. The finish. These oil based urethanes/polyurethanes (aka SOLVENT BASED finishes) turn orange all by themselves. We call it "ambering". If you paint white paper with a coat of the oil finish, it will dry ORANGE.

So...the "fix" = strip it down and do it all over again with a water based finish. That's it. That's the fix. That's why you always view the colour patch with the a single coat of finish over top...and then view it for a full 24 hours before deciding.

I'm sorry but this is a complete redo - probably at your expense. They have to get down to bare wood, apply a water based stain and then finish with several coats of high-end water based polyurethane. The water based finishes dry "colourless" or "clear". That's why they are called "clear coats".

Good luck. If you have the budget to have this done over again ($2-$3/sf because the sanding is done...they just have to strip it down and start with the stain) then you can move forward with a redo. If it is not in the budget then you probably have to live with it for the next 15 - 25 years.

@hollycbs....the oil based finishes are the originals from 100 years ago. They developed to take over from the labor intensive lacquers (a real lacquer finish is HORRENDOUSLY difficult/expensive to put down). The oil based are the original 'solvent based' finishes. But Mr. and Mrs. Joe Public got scared of the word "solvent" (it sounded dangerous and unhealthy...which they can be) so the finishing industry simply changed the word to "oil based". No change in formula. Just a name change. Reprinting labels for thousands of gallons of material is SUPER cheap....like $0.15 per label. Changing a FORMULA is expensive (imagine 100's of chemists working hundreds of hours and hundreds of tests run to discover they don't work).

So...why do they use them? Because they are industry norm. You have to specify SOMETHING ELSE. The 'basic' package comes with the cost of the cheap oil based finishes with their cheap oil based stains (Minwax stains are oil based). Materials are cheap. They are easy to work with and have been around (which means everyone trained on them) for 100 years.

Cheap materials = more money in the pockets of the refinishers. Unless you specifically ask for "water based" finishes or a "clear coat" (which means you have to know that the oil based finishes turn orange in the first place), the installer will simply use what s/he always uses....oil based finishes.

And many people LOVE the depth of colour the oil based finishes create. You are someone who does not. It is a sad lesson to learn this late in the game. I'm sorry this has happened. If you can learn to like the colour, you would do well to leave it be.

Interesting, and good to know! That explains why I don't like so many wood floor offerings as I hate the orangey-yellow tones.

https://www.familyhandyman.com/floor/water-based-vs-oil-based-polyurethane-floor-finish/view-all/

https://www.valentiflooring.com/blog/oil-based-vs-water-based-polyurethane

Indeed interesting discussion. I was happy with oil-based stain for my outdoor projects in the last couple years and I am actually quite impressed with what it can do. It has brought back life to a lot of weathered wood and bamboo. Recently I got fed up with the amber tone that always comes with it and was looking for something that is a little more 'crispy' and doesn't have that dull amber tone. From the discussion above it looks like I will have to switch from oil-based to water-based.

Yep.

We just had our deck sanded down and stained and I loved the way it turned out. Today he put on an oil based polyurethane and it completely changed the color to more of a brown. Can you add another coat of polyurethane with a tint to change the color?

@Gina You don't want to go that route. The oil based polyurethane is what caused the change. An exterior grade finish is very different from indoors. Your poly on the deck will last a few years, and then you get to do it again. I would just relax and enjoy. Once you get things set up and area rugs in place, etc, you probably won't notice it (assuming this is NOT a massive wrap around deck).

The only way this could have been prevented would have been to view the sample colour with a coat of the finish applied over top. But outdoor finishes do not get the same consideration as indoor finishes.

I'm sorry this has happened, but short of starting over, you won't get what you are looking for by using a tinted poly. And tints added to poly can often degrade the adhesion properties (the coat won't want to stick to the original coat) which OFTEN leads to a homeowner being less than happy with a cracking, splitting, peeling finish.

So sorry this has happened. Good news is, you will get your chance to do it over in a few years.

"We just had our deck sanded down"

"Today he put on an oil based polyurethane"

Polyurethane on a deck?

I wouldn't