Yves Saint Laurent Touche Eclat Le Teint Long-wear Glow Bd-25 Warm Beige 25ml Foundation Foundation is a liquid, cream, or powder makeup applied to the face and neck to create an even, uniform color to the complexion, cover flaws and, sometimes, to change the natural skin tone.Some foundations also function as a moisturizer, sunscreen, astringent or base layer for more complex cosmetics.