I think it depends if you are talking about the sleeveless 'vests' or the tops.
I have both. They are plain colours ( not that it should make any difference.)
The vest ( no sleeves) rides up if it's not tucked into my jeans or tights- it's quite short as it's an XS size.
The tops with a scoop neck and long sleeves tend not to ride up so much because they are longer on me.