It is very cute, but the Medium fit me like a Large.  I then ordered it in SM, arrived just now, and it's perfect! Still plenty of room to cross arms, since the back ventilation "shawl" is roomy--it does come down farther than most shirts like this, but seems more stylish.

Big plus: FINALLY a roll-up sleeve that covers more like a 3/4 sleeve (for the M, just below the elbow for the S).  Most hit above elbow and are NOT flattering!

The "fossil" color is sort of like the old Necco chocolate flavor wafer candy.  Will not show dirt much.

The "button-down collar" uses velcro so tips can be easily opened to lay spread out.

There are TWO zippered pockets near the waist.  These will be fabulous for travel.  (PS I threw away one shirt--another brand--that had chest pockets.  Unusable because they make you look lumpy, VERY unflattering, and if you tried to unbutton some top buttons, the mesh lining hung out like bad underwear.)

AND the "Columbia" tag is velcro-ed so that it could hold a water tube or lip-balm.  LOVE this shirt!