I have pine floors throughout my house. When I bought it, they were damaged with lots of scratches and the colour had faded to an orangy shade. The floor was quite soft in areas also.
I hired someone to refurbish them- they sanded the floor and stained them a dark oak colour. They looked fantastic when done.
A few months on and in parts of the house, the colour had faded badly, you can see the yellow coming through significantly.
The workman who did them was a lovely guy, but I got the impression half way through that he wasn't that experienced. Anyway, I've contacted him about it and he looked and says it must be because there is excess moisture in the wood and that's what is causing the fading as the top coat is still intact.
I am feeling that if the top coat is intact, it obviously shows there was no wear and tear causing the fading so the job must not have been done very well. The house has actually been empty for the last month. However, as I am aware that the floors were not great to start with, I don't want to insist on him fixing them if it's not his fault. I can't help thinking though that if the floors weren't in a position to hold the stain, he should have known that when he said he could do them no problem. I'm no DIY expert though so I could be being unreasonable?