White sauce is used in various recipes, such as fettuccine Alfredo, lasagna, cheese sauce for macaroni, or as a sauce to go with chicken or fish. When too much salt is added, the taste becomes unpleasant. However, the sauce can be salvaged with various techniques, or the addition of certain ingredients.
Add more water, milk or low-sodium chicken broth. Be careful not too add too much because the sauce will be too watery. If you made a large batch of sauce that was too salty, add a 1:2 ratio of liquid-to-sauce.
If you're making a pasta dish, add more pasta. The pasta will absorb the sauce and reduce the saltiness. If it's a vegetable dish, add more vegetables, such as potatoes, celery or carrots.
Add more herbs. For example, if you're making a sauce to go with baked chicken, add herbs which will compliment the flavors of the chicken, such as basil, cilantro, thyme, rosemary, oregano or parsley. Also add a few teaspoons of lemon juice to bring out the flavor of the herbs in the sauce.