"Ombre" is a French term meaning shaded. Mainly, it refers to fabrics meaning a gradual change in shade from light to dark or one color to another. It is the newest trend with hair color as you may see many celebrities on the magazines with what can resemble a grown out highlight. Here are some examples:
It can be range from a more subtle ombre to a more contrasting/drastic look. More of the subtle look is what is the most flattering and gives the illusion of sun kissed highlights. It is actually achieved by "melting color" from the roots down to the ends as it gradually gets lighter. You do not see a line of demarcation as you would see if you just let your highlights grow out. This is perfect for the client who doesn't want high maintenance hair but wants some highlights. You will see this a lot in 2011!