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The setting to be used is iTunes 12 > Preferences > General.
Unfortunately, iTunes gets to choose, it seems, the background color based on some key color of the item's art. Sometimes it can look really nice, like my iPhone's playlist for walking, shown below on iTunes 12 on a Mac.
This color generally carries over to synced playlists on an iOS device, but may be altered, I discovered, based on color choices in Settings. Other times, the iTunes choice can have poor contrast for small type and cry out to be turned off, especially in bright sunlight—as in this example on my iPhone.
Again, unfortunately, this feature cannot be managed, so far as I know, on a per playlist or album basis. I've found that it generally looks okay, but the choices made by iTunes probably won't suit everyone.