replace most of the color variations with v2 like skins

[danny007in]

[BREAKING CHANGE][REDUCE FILESIZE]

[REJack]

We should keep the custom Border & Background colors they doesn't bloat much, and it's still nice to use multiple colors for cards instead of only the 5 default bootstrap colors (Primary, Success, Warning, Danger & Info). The biggest concern was all the Sidebar variations that caused too much pseudo-classes.