- It’s caused a serious stir – and when you snap up The Ordinary’s Serum Foundation (if you’re fast enough!) you’ll soon see why. Formulated from a unique combination of colour pigments suspended in the brand’s proprietary ‘spreadability system’, this lusciously lightweight serum glides on for a smooth, subtly perfected, semi-matte finish that lasts all day without settling into fine lines. For an ultra-natural result, it’s available in 21 versatile shades, ranging from very fair to very deep and each classified according to its undertone. ‘P’ shades stand for pink undertones, ‘R’ for red, ‘N’ for neutral and ‘Y’ for yellow, so you can suit your skin tone to a tee. As if you needed further convincing, the formula also offers SPF 15 sun protection without the use of chemical sunscreens.