Olive green is a color that will always be in, so why not get the softest olive green tee? This is a One Size fits all. So if you are a size XS or S it would be an oversized tee, but a M or L would fit more like your typical tee, still a little oversized but more true to size.
Marissa usually wears size L and Katrina wears an XS. Marissa has hers tucked in just in the front and Katrina knotted hers to the side.