Trying to find the right shade Of foundation

I am a middle -age Iranian with an olive skin. I have red spots on my cheeks and nose. I don't have lupus but I have these redness. I heard that Lancome Teint Idole Foundation is perfect for me. I just don't know what shade I have to buy. My skin used to be oily but not anymore. I don't have time to go to the store. Ant suggestions? I have sensitive skin and need full coverage all day.

Thanks

Toubi