Like your clothes, each piece of jewelry has to match with your skin tone.
It is therefore important to choose pieces of jewelry that not only match with your outfit, but that also enhance you. Opt for metals and gems that illuminate your natural skin tone. There is a wide spectrum of different colors: gold, silver, sapphire, amethyst, etc. Maybe turquoise goes better with your eyes than ruby. Silver is the favorite metal for many of us, but if you have the matte skin and dark hair, gold is beautiful!
In short, criteria such as the color of your skin, your hair, and your eyes are just as important in choosing your jewelry as it is your clothes.