Mine is silver, and I've had it for about 2 years. No real notable difference minus two aspects;
1) The magnetic part where it clips onto itself is fully of scratches all over and slightly less shiny due to that
2) Some parts of the band have less shine/has dirt (appears almost black-ish) on the underside/where it loops against itself in lines (any visible part when wearing looks shiny, brand new).
I'm assuming this is probably because I have the silver coloration, whereas with the dark coloration you probably wouldn't notice 2) and I'm not sure how 1) would be after time like mine. I wear mine basically 24/7, unless I'm swimming, in the shower, etc. No complaints from it being uncomfortable over time as it feels just as comfy as the first day.