Well, whatever color you like! Are you wanting to maintain a natural appearance, or go for something more risky or fun? Do you want a solid color, highlights, lowlights, blocks of color, etc? This is a question better suited for a hair stylist to answer, however, be careful where you go to find your answer. Make sure whatever stylist you ask is experienced with color and not afraid to try something new (many, like my old stylist, get into a funk where everyone's hair looks the same as the last persons when they leave the salon). With your description of skin coloring, it sound like you may be safe with almost anything you choose. If you opt to do at home color, be careful. Most at home colors turn out darker than what the picture shows. Also, your hair may have a tendency to pull out certain dominating shades, like red, from say a neutral looking brown. You will be taking more of a risk by doing this yourself, so keep that in mind. Good luck!
a nice auburn color would be perfect for the winter season, and it pretty much compliments any skin tone. you could also try a nice chic black as well. if you have any question, just pop into a salon and they would be happy to help you pick out a color that would flatter you!(or more importantly, tell you what not to do!)
I think coloring it a very light brown or a very dark blonde would be very pretty. When you go to get your hair colored, discuss different color options with your stylist and he or she should have some color swatches of different shades for you to choose from. However, it would be good if you could find a picture of a hair color that you really like so that you can take it with you to show your stylist.
I hope this helps you.