Editor’s Note: This feature is part of Colorscope, an award-winning series exploring our perception of color and its use across cultures, one shade at a time. See more here. When you’re next ...

In fact, it’s an inherited trait that dates back to our early ancestors—about 10,000 years ago, every human ... eye color runs the gamut from very light blue to very dark brown.

But zoom in to see just how ragged it is on a microscopic scale. Our fine hairs look like tree trunks under a microscope. Don’t be fooled! That’s not human hair—those are super-soft cashmere ...