Why does my iPod Touch show Spotlight differently?

I have an iPod Touch 5th gen (latest). After I upgraded to iOS 8.2, the Spotlight display looks like the following. Instead of the icons fading out to nearly invisible (as it does on my iPad and an iPhone 4S I tried), the icons are shown in chunky black and white.

What's going on here? Why does this happen on my iPod Touch, but it works correctly on both older and newer hardware? Is this simply a bug in iOS 8.2? Does this happen for anybody else?