The best hair color for you will hinge on three things: your natural hair color, your eye color, and your skin tone. The most important of these is your skin tone. Your skin tone will fall under one of four coloring categories. The first is dark, the second, olive, third peaches and cream, and last fair to light. You'll need to base your hair color on your skin tone, with those who have warm skin tones being those who look best in jewel tones and those with cool skin tones being those who look best in earth-toned clothing. Another trick is to look at the veins in your arm and see if they're blue (cool, blue undertone), or greenish (warm, yellow undertone). Other attributes of warm and cool skin tones:
You'll do best to stay in your natural temperature neighborhood, by which I mean that you must have some idea of what your skin tone and hair color originally were (before tanning and dying). Your natural coloring will always come through a little bit no matter what you do, so respect it and do not ignore it.
For the warm hair colors, you'll want to stay with yellow-, golden-, and amber-based colors, and for cool tones, stick with ashy colors and black. Basically the chart above can help you out with getting some color inspiration for your next dye job. You can easily see what colors of hair people with your same coloring have been successful with and that have looked natural on them. And what's better than looking like you were naturally granted the most beautiful hair possible?