I have natural yellow colored dirty blonde hair as Sofia Vergara, and I am looking for some highlights for my hair. I am 15 and I have never colored my hair. Somehow, my friends donât believe until now, that my hair color is natural, but anyways, I was thinking of some cool color as undertones on my hair, that would look great on my age. My boyfriend has advised me to color some parts of my hair in dark brown, but I am not sure whether it would look good or not, as I have a slight dusky complexion, and my hair is just medium length. Can you please advice of some great hair colors as undertones for blonde hair as Sofia Vergara for me at 15? Please help!