Cannot make "Library source color" setting appear

On the Settings - Interface - Theme, font and colors page there is a screenshot that shows a Library source color setting. I cannot see this - how do I enable it?

Before I had it configured so that browsing my library significantly took on the colours of the artist/album art and I’d like to restore this behaviour. Is this possible?

Please note that I am not talking about playing media, I am interested in library browsing.