For a style that really stands out, consider darker gemstones like sapphire, amethyst, or blue topaz. These vibrant gemstones range from modern to classic depending on the ring style and metal color, making them surprisingly versatile. Other bold choices include tanzanite, ruby, and garnet. Whatever the color of the gemstone, you can also choose a design with a large or fancy-shaped center stone. A halo is another beautiful way to draw attention to your center stone.