Mayonnaise usually has a white color to it but if yours has turned to a light yellow it is time to throw it out because it has most likely gone bad. It is extremely important for you to be able to tell whether or not your mayonnaise has turned, simply because you will want to avoid succumbing to food poisoning, especially because it can be prevented in the first place with a few simple observations.

Mayonnaise that is still good to eat has a white color and is not yellow in the slightest. Sometimes if mayonnaise is left out long enough, especially in an unrefrigerated environment, it can grow mold which is a sure fire sign that it has gone bad altogether.