Gilding the Lilly 

To adorn unnecessarily something already beautiful. The expression is a condensation of Shakespeare's metaphor in King John: "To gild refined gold, to paint the lily ... is wasteful and ridiculous excess." i.e., you wouldn't need to add gold to a beautiful lily.

Jennilyn is so beauitful that putting on makeup is just Gilding the Lilly.

Gilding the Lilly by _Andy_ June 24, 2006