Fiberglass insulation, sometimes referred to as glass wool, is a fluffy insulating material used to fill spaces and walls in homes and buildings. Pink fiberglass insulation is the most common color available, but other colors such as yellow and white are also seen throughout various construction uses. The primary difference between different colors of fiberglass insulation is the manufacturer.
Different colors are added to fiberglass insulation for the specific purpose of identifying the manufacturer. Because fiberglass insulation is a soft material and covers wide expanses of buildings, it can be difficult to label all of the insulation to identify the manufacturer, so colors are used instead. Pink and yellow fiberglass insulation merely come from two different manufacturers. Owens Corning produces the pink fiberglass insulation and has trademarked the color pink when used for fiberglass insulation, while yellow fiberglass insulation is produced by nearly every manufacturer that doesn't use a specific color such as green or white.
Blown-in fiberglass insulation comes in white, pink or yellow and is blown into a space with air instead of being installed in pieces, which are called batts. Older types of blown-in insulation are normally yellow, as white and pink blown-in fiberglass insulation can appear yellowish as they age or become dirty.
While pink fiberglass insulation is essentially a name brand product, yellow insulation is the default color for most other fiberglass insulation manufacturers. This can result in generic or foreign-made brands being yellow. Not all countries have the same safety restrictions or regulations as the United States, so consumers and contractors should be careful when they purchase yellow fiberglass insulation for which the country of origin or manufacturer cannot be identified.
Fiberglass insulation of any color can come with health risks. While fiberglass is soft, it is still composed of tiny glass fibers that can be sharp or irritating if they get into the eyes, are swallowed or are inhaled. They can even result in severe skin irritation, so plenty of protective gear, such as respirators, eye protection and skin protection, should always be worn when working with it.