>>714712445
Look at the second picture. When the sun has an angle to touch her roots, they appear bright. Her roots aren't dark. The sun simply wasn't hitting them, so they're at two different white balance levels. It's nothing but a trick of the light.

As for her eyebrows, before I believe they're natural, I would have to believe that she didn't use make up to darken them. Which is what a lot of girls do. Some people dye their eyebrows darker. Take a look at the filename from this pic >>714696581
People with light eyebrows often dye them.
There's also the option of tattooing eyebrows.
Never assume a woman is all natural. That would be a huge mistake.