Wear and laundering of fabric articles, and particularly white fabric articles, can result in a discoloration from the original fabric color. For example, white fabrics which are repeatedly laundered can exhibit a yellowing in color appearance which causes the fabric to look older and worn. To overcome the undesirable yellowing of white fabrics, and similar discoloration of other light colored fabrics, some laundry detergent products include a hueing or bluing dye which attaches to fabric during the laundry wash and/or rinse cycle.
However, after repeated laundering of fabric with detergent containing bluing dye, the bluing dye tends to accumulate on the fabric, giving the fabric a bluish tint. Such repeated laundering of white fabric articles tends to give the articles a blue, rather than white, appearance. To combat this accumulation of bluing dyes on fabric, chlorine treatments have been developed. While the chlorine treatment is effective to remove accumulated bluing dyes, the chlorine treatment is an additional and often inconvenient step in the laundry process. Additionally, chlorine treatment involves increased laundering costs and is harsh on fabrics and therefore undesirably contributes to increased fabric degradation. Accordingly, a need exists for improved laundry detergents which can counter the undesirable yellowing of white fabrics, and similar discoloration of other light colored fabrics.