Black fiberglass is a specific type of fiberglass that is dyed black, which gives it a distinct appearance and makes it suitable for applications where a darker color is desired. Other types of fiberglass can be clear, white, or colored, depending on the application and aesthetic preferences. The primary difference is in the color and possibly the additives used to achieve the color. Functionally, they all serve the same purpose of reinforcing materials, providing strength and stability, but the choice of color can affect heat absorption, visibility, and the overall look of the final product.