To choose the appropriate colour of jewellery, you need to look at the undertone of your skin. If your arms show mostly blue or purple veins in natural daylight (cold undertones), you should prefer white gold and platinum. Do your veins have a green, warm undertone? Then yellow gold is recommended. If you see both blue and green veins, then both shades of precious metals will match your neutral undertone. The black mineral onyx is often used in cufflinks due to its neutral, very stylish look.