The problem is that the EXE likes being efficient. It assumes that because it has already loaded the file 'floor.bmp', it doesn't need to reload it again. The Batman Arena, Event Results Arena, and Practice Arena all load the 'floor.bmp' that you see but the Luma Zone's real 'floor.bmp' looks completely different.
To fix it would require some minor GMF work and file renaming.
Another arena that you might notice a minor skin change in is the DSL Tournament Arena after visiting the DSL Lava Island Arena.
Floor saw plates can be either yellow (Half Circle Arena) or orange (Combat Arena) depending on which arena you go to first.
If you want to be really technical, triple spike plates can be either a dark orange (Bridge Arena, Compressor Arena, Half Circle Arena) or a light orange color (Combat Arena, Skull Arena).