Use cool to warm, not hot, water. Wash colored linens in cool water. Launder stains when fresh. If allowed to set, stains may be permanent. Experiment to see how much is needed.
Chlorine bleaches can cause yellowing.
Try a couple of tablespoons of cream rinse for your hair in the final rinse cycle. Linen is cellulose fiber, and many of our customers swear this makes their linen more lustrous. If hand washing, rinse very thoroughly. Removal of all soap will help prevent large brown spots on linen, which are caused by oxidation of cellulose by residual soap. Whatever method you use, bring the linen in while it is still damp.