Always read and follow the care instructions and any warnings on the garment label. And, follow the General Rules for washable fabric stain removal.
Some fabrics which are white or pastel colored contain optical brighteners or fluorescent whitening agents (FWAs) which were applied during manufacturing. These agents can decompose when exposed to light and atmospheric conditions, or prolonged storage conditions. In some cases the entire fabric becomes dingy or develops a yellow cast. In other cases the yellowing develops only where exposed to light. The FWAs can also be damaged by the use of chlorine bleach.
Unfortunately, once the FWAs are damaged, the whitening agents can't be reapplied to the fabric.
All fabric bleach or the use of speciality products available in grocery or drug stores, such as Rit's "Whitener and Brightener" may help. Carefully read and follow the instructions on the product label, and check for colorfastness first.
ZYIA - Item 793 - Black Brilliant Hi-Rise Leggings 28
The most versatile of all workout clothing, our brilliant performance legging reigns supreme. The high, structured waistband comes right to your bellybutton and won't dig, pinch, or tug as you move. Flat-serged seams inside and out— plus 25% Spandex content—provide the wear-all-day comfort you demand from a quality legging.
ZYIA - Item 3535 - Men's Army Green Crew Sweatshirt
If you like to layer on warmth without adding fleece, this Terry sweatshirt delivers that classic cotton feel and weight you love, without the fuzz. Effortless to wear and to care for, this relaxed crew top makes good on the classic sweatshirt promise of comfort, flexibility, and durability.