Some fiberglass insulation is yellow, while other fiberglass batts are white or pink. What’s the difference?

Manufacturers use different colors to “brand” their version of fiberglass batt insulation. Owens-Corning has trademarked its pink-tinted fiberglass. John Mansville produces fiberglass insulation that’s white and green. Yellow is another common color. The color is provided by the resin-based binder that helps to hold the spun glass fibers together. Thermally, the differently colored batts perform the same, offering an R-value of about 3.14 per inch of thickness. If you see a batt with black stains, this is usually a sign of air leakage near the stained area. One shortcoming of fiberglass insulation is that it doesn’t stop air movement that can contribute to energy losses. Instead, the glass fibers act as a filter, trapping the dust that causes the black stain.