Message in attachment format has wrong left border color in version 3.0

There is a bug when posting message in attachment format with named color style, as screenshot below, the good style .attachment__container--good should be #00c100 (green) but was overridden by the .app__body .attachment .attachment__container which is #2f81b7 (blue).

Screen Shot 2016-05-23 at 12.10.52 AM.png1730x1240 216 KB