It was either made without bromides, or was added later to the machine, or it just aged much better than the original bezel did!
The vast majority of Zip drives were 3.5 inch beige IDE units. Iomega briefly made rather handsome 5.25 inch blue SCSI units to match their external drives, which I was super lucky to grab at auction this time last year:
But I had no idea that larger unit also came in beige. I suppose it makes sense; the blue was fetching but didn’t match the cases at all at the time. Or today’s modern PC cases, which like the Model T come in any colour you want as long as its black.