I have a hard time finding the right foundation color and formula too. But I am loving Eveyday Minerals. I was using my favorite MAC foundation for years but had to switch when I got pregnant because it had a vitamin A derivative in the ingredients.
Anyway, Everyday Minerals has 3 different formulas for the different skintypes and a very large range of colors which you can actually mix and match yourself to get a custom foundation. They have a range of colors in the "olive" family too. It is also gentler than Bare Essentials which actually has an ingredient known to irritate sensitive skin.
Best of all Everyday minerals offers FREE samples. They are generous too. It's been about a month and I'm still using my samples (no where near finished yet too). Sample kit includes 3 foundations of your choice, a blush and a concealor. I love the blushes that I got but the concealor was kind of "meh". Maybe I haven't found the right one for me yet.
You just have to pay for shipping which for me was about $3. I only had to order 2 sample kits to find my match so I only paid $6. Their full sized foundation is also way cheaper than Bare Mineral.
The application is a bit different from regular foundation though but it's fast and easy once you get the hang of it. Some people use a brush (I recommend a Kabuki type brush or flat top). Right now I'm loving the flocked sponge (you can get a pack in drugstore for a couple of bucks).
Anyway if you are interested just google Everyday Minerals. If you are interested in makeup/beauty reviews from real people, check out Makeup Alley (just google them). That's where I go first before buying anything with my hard earned money. Some of the reviews can help you figure out which colors/formula to get. And they have a message board so you can ask all your beauty questions.
Okay...enough rambling! :) Hope this helps. I know how frustrating it can be! I spent years finding my perfect foundation (the MAC one). Luckily it only took me a couple of tries with the Everyday Minerals (thanks to internet resources like Makeup Alley!).