Two-tone square eyebrow powder The two-tone square eyebrow powder is a product that includes two shades of powder, packaged in a square compact. It offers both dark and light colors that can be blended to help you create naturally defined brows. The darker shade is ideal for outlining and defining the tail of the brows, while the lighter shade is perfect for filling in the front, creating a soft transition. The compact square design makes it easy to carry, making it an ideal choice for daily makeup.