"rosy red" is correct and usable in written English.
You can use it to describe a color or to give an emotional quality to something. For example: "The rosy red sky at sunset was breathtaking."
Highbush blueberry shrubs, their foliage rosy red, are scattered throughout the eastern-facing slopes.
Rosy red, I was ready to plunge back into the grit of Marrakech.
A rotund Finnish gentleman with rosy red cheeks, a jolly manner and a bellowing laugh?
So I've gone for a rosy red, a kind of New New Labour red.
Now the nails of a midcentury screen siren — long and almond-shaped in rosy red — feel dangerously modern.
On downy white breasts, rosy-red nipples had become all but vestigial.
Look, there's the humble flowering currant, Ribes sanguineum, whose rosy-red racemes mark the beginning of spring.
Five beautiful rosy-red tuna slices (from the loin of a blue-fin tuna), smooth and tender, were superb.
The crops were jade green; the flowers were in bloom, releasing their perfume into the air; the skylarks sang in the rosy-red sky.
Sometimes, Bramley apples can flush orange, with broad, red stripes that make them look very rosy-red, though this usually happens on only one side of the fruit.
