One thing people might not realize about gray hair is that it can develop a film from environmental resins. Whether they're byproducts of conditioners that coat the hair reacting to ultraviolet rays, deposits from low quality air including cigarette smoke or simply a buildup of styling products, there are a few ways you can get rid of the yellow that's making your gray hair look dirty.
If your buildup is caused by styling products, conditioners or cigarette smoke, you can remove it by giving your hair a clarifying treatment. Purchase an over-the-counter treatment kit that's gentle on your hair from a beauty supply store, or use a clarifying shampoo every week. For daily maintenance, add a tablespoon of white vinegar to a half gallon of water to rinse with. The odor goes away when your hair is dry.
Counteract the Yellow
You can use an old-fashioned bluing rinse to counteract the yellow. The rinse is available at grocery and drug stores. It's easy to use at home, and can even be sprayed into hair that's been towel dried, if you're concerned about your skin getting stained. If you're having your hair done every week, ask your stylist to add a blue rinse. It's an inexpensive procedure that doesn't add any extra time in the chair.
When silicon-based "smoothing" products are affected by ultraviolet rays, the silicon itself turns yellow, causing your hair to look like it has a yellow film over it. Be sure to remove the buildup of silicon on a daily basis to keep hair crisp and clean looking. Avoid smoking cigarettes or visiting smoke-filled rooms because the smoke can settle on your hair, just like it does on the walls of your house.