Yellow onions are by far the most versatile and popular as of 2015, comprising 87 percent of U.S. onion crops. Red onions are around 5 percent of the country's crop, and white onions are the remaining five percent of production.
Yellow onions are sweeter and better for caramelizing, with heat bringing out a nutty and sweet bouquet of flavors. They also have longer shelf lives, contrary to their white counterparts. Red onions are popular for salads and sandwiches because of their attractive red to purple hues. White varieties are more popular in potato or pasta salads, white sauces, and Mexican or Southwestern cuisine.