I may be one of the first on this site to put a Mustang style scoop on a ST.
This is an actual Mustang scoop, modified to fit the ST's hood contours.
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I vote for matching the body color. White on white would look good. If the edge of the mounting tape will show (which it probably will), put a couple of coats of Ford white touch-up paint along the edge of the tape before you mount the scoop. That way you won't have a visible black line afterward.