Sephora carries a brand called NVEY ECO that offers a certified organic foundation in a compact with ten skin tones to choose from. What is impressive about this product is each shade offers a coverage for a certain type of undertone, which is extremely hard to find in regular drugstore brands, with or without any type of organic or natural certification.
Beautorium offers a product called Logona, which is organic. The foundation is liquid, but only comes in two tones. This one is less expensive than NVEY, but only for light skin tones.
If price is an issue for you, as it is for most people, natural products are a great way to try out a new and innovative product, without breaking the bank. Even though natural does not mean organic by any means, it is still a step up from products created with almost purely harsh chemicals that can actually damage your skin.
Physicians Formula created a new brand called Organic Wear 100% Natural Origin Makeup, which is ECOCERT certified. Their Loose Powder works as a foundation with buildable coverage and comes is six skin shades. Perk: This product can be found at your local drugstore.
Origins is another brand that is natural (read their purity statement here) and they claim to use organic ingredients whenever possible. If you want full coverage for a reasonable price, try Next of Skin. It is a very full coverage foundation that lasts all day, and is very hard to rub off. It can even be used as a concealer, layered, if you are in a hurry. This foundation comes in fifteen different skin tones and blends flawlessly.
No matter which foundation you choose, make sure it feels right to you, and try to pick the one that appeals to you the most in texture, coverage, and even its scent. All of these can make an impact on the way you feel throughout the day, especially if you love wearing makeup.