BBS doesn't support alpha-hex notation

Hello,

BBS doesn't seem to recognize color like #000000AA (where AA is the alpha value). It would be awesome to have this implemented (it's working fine in the browser).

Thank you for this suggestion! Not all modern browsers have support for this color format yet. We don't want to encourage its use until it is more widely supported.

I use rgba() for my design without particular compatibility issues. And BS4 supports modern browsers only. (Dropped IE8, IE9, and iOS 6 support. v4 is now only IE10+ and iOS 7+).

https://caniuse.com/#feat=css3-colors