@Ana1234 - You can still experiment even if you've found a shade that really suits you. You might get different effects depending on what other makeup you're wearing, or the time of year. An olive complexion doesn't change as much with the seasons as a paler one would, but it can still darken in the summer (or appear to darken when you're wearing certain clothes).
I have relatively fair skin from my Irish mother, but it's got a yellow undertone from my Middle Eastern father, so I come close to having an olive skin tone when I'm tan. I try not to get that tan these days, because I don't want the sun damage, and it's a pain having to swap around my makeup as well.