"The neck is one area that doesn’t get much sun," Quynh says. "If your face is light, then your neck is even lighter, so definitely use foundation." Blend it well to avoid a line near your chin and jaw.
Roncal says to match the colors on your face, neck, and chest as closely as possible. "Choose a foundation that matches your collarbone," she says. You may need to switch to a darker color in the summer if you tend to tan.