Conservatory different shades

er_indoors

We recently had a new conservatory fitted in white upvc. The problem is that although the exterior roof and windows are the same shade of white, inside the roof parts are a different shade, More of a cream than the white doors and window frames. I bought a cream light fitting and this really shows up the shade difference.

The company that it came from are saying that its just a problem with different manufacturing runs. That shades can be slightly different and really nothing can be done.

This can't be right can it? If you buy a white conservatory is it unreasonable to expect it all to be the same colour? If I bought a suit and the jacket was a different shade than the skirt then that wouldn't be acceptable. I wonder where I stand in consumer law. Tyvm