Note the sleeves on the model. that is how your regular size will fit your arms. however, even if you have skinny arms like i do, the sleeves will be tight. i bought my regular size xs and it was clingy with an odd flair and the length seems as though i ordered a petite and i am only 5 ft 2 in.
i advise to try a few sizes on if you really are interested. the red is truly a red which is a good thing because so often it is hard to find a red that is not neon.