Product review (3 stars): Paint/Enamal Issue
Two points.  The first is minor.  The color of these grates are not black/black.  They have a greyish tint to them.  Still look good on the cooktop, but just beware.

Now the issue that drops my rating to 3 stars.  After about one week of use, the coloring on top of each grate that has been used is scratching off.  Our pots and pans have smooth bottoms so this should not be an issue, but it is.  There must be a slight enamel/paint ridge on top that the cookware removes.  This is leaving a thin silver looking scratch on the grates.  Not visible unless you are close to them, but annoying to be sure.