Traditionally gives a gold ring, but nothing prevents you choose silver, platinum, titanium, palladium or, as we have said, stems from daisies. I personally prefer white gold to yellow. Here’s the place to say that white gold as a chemical element exists; It is embroidered yellow gold. Note that in time the ring will turn yellow, but almost all jewelers offer rhodium bath, which is easy and safe procedure and restores shiny white ring. The addition of copper, zirconium, indium and aluminum to gold even lend respectively pink, green, blue or purple hue. Platinum is harder, tougher and more expensive, so it is recommended as the best friend of the diamond. Silver protects from evil forces, but is relatively soft, so really careful if it’s your choice. Titanium is the metal of the future generation, and palladium is hypoallergenic and symbolizes the invincibility because of its hardness. What would be your choice, leave entirely to you.
In cross-section of the ring, check that form inside oval (most jewelers similar form called “comfort fit” or comfortable). The difference between the flat and comfortable inner profile is huge.