Change of color after flair restart

Dear amario

Good afternoon, Thank you very much for your answer, i now have a very confused question. I was opening the same inp file above, but when I upgraded the FLUKA version, geometry was wrong, I don’t know if it was a problem, or my illusion, do you have any relevant insights?

Liking the figure below, how did the floor brick of the interior space become black?

Sincerely looking forward to your reply, I wish you a happy work!

That is the image before updating FLUKA and FLAIR

As you can easily imagine, it is very difficult to answer your question, not knowing what exactly has happened.
What I can tell, is that in the image below, the same material is assigned to the floor and the walls, while in the image above, the floor, being of a different color (dark but not black), has been defined as made of a different material.