Rose gold fill is exactly the same as gold fill, except that copper is mixed with the alloy to give it its standout rosy hue. In other words, both 14k gold and 14k rose gold contain the same amount of gold—the only difference is the combination of other metals that are added to the pure 24k gold to create the 14k gold alloy.
When it comes to gold-fill, rose gold follows the same specifications as yellow gold, with a thick layer of 14k gold over a jeweler’s brass core. The only difference is the color of the gold—one is 14k rose, the other 14k yellow. Both 14k yellow gold and 14k rose gold alloys contain the same amount of 14k solid gold. It’s the combination of metals that are added to the pure, 24k gold that changes the color—the pure gold part is that constant 58% of the alloy.
For more information, read about gold fill.