Bold Yellow mustard seeds are a common type of mustard seed, and "bold" might refer to a specific variety or grade of mustard seeds. Mustard seeds come in different varieties, and they are often used to make mustard condiments, spice blends, and for culinary purposes. These are the seeds of the yellow mustard plant (Brassica hirta/Sinapis alba). They are known for their mild flavor compared to brown or black mustard seeds. Yellow mustard seeds have a mild and slightly tangy flavor. Bold Yellow mustard seeds, in general, are rich in nutrients, including selenium, omega-3 fatty acids, and magnesium.