That looks like the upper section of that door was older, with dirtier and/or a differing moisture content wood. It might have needed cleaning first with something like a mild deck cleaning solution.

Okay, so what should we do now?

One other possibility, a different type of wood in the top half of the door. It might have been a manufacturing mistake. If that's what it is, you need a new door, or at least new door sections.

Did you take pictures of the doors before they were Cetoled? If you did, and the difference is detectable in the photos, you have two choices. You can ask the door supplier to replace the door, or you can ask the painter why he didn't prep it properly.

In the unlikely event the supplier provides a new door, your problem is solved. Otherwise, you can insist that the painter strip the door and preps it properly.

As an alternative, you could just turn the matter over to the door supplier, pointing out that it has to be the door and insisting that he fix the problem, or at least come up with a solution.

If those are real high-end doors, the manufacturer might actually be embarrassed enough about it to do something. If the dealer won't help, contact the manufacturer directly.

If the doors were purchased through the builder, go though him first.

Good luck.

There was no difference before the stain that was obvious, but honestly I did not look too closely. They are all cedar. I did ask my builder to talk to the painter to see if anything was done differently. It's possible, it was a different batch/age of wood. Is there anyway to manipulate the stain to even it out a bit? What if we put another coat of the cetol 1 on all the doors?

Sorry, I can't answer that. I have used a lot of Cetol on teak and mahogany, but never on cedar. I think that door has to stripped, sanded, and recoated. However, if the wood itself is a different shade, I don't think anything will help.

With segmented doors made of wood, the wood needs to be matched, top to bottom. It think the first order of business is to find out if it is matched wood.

I think what might have happened is that they ran out of wood half way through that door and ordered more. But obviously, since it was a different batch, it took the stain differently. Well, if we can't figure out a way to remedy it, they will need to build us a new door.

Discoloration is shipment/storage. I call it "sunburn". Whatever part is exposed to more light, air or weather will change color.
Casey