Alert Boxes [Shortcodes]

Do you think you may add Alert Boxes to your short codes list? I really don’t want to use a plugin. Looking for something easy with icons.. maybe like this:

http://demo.mythemeshop.com/spike/shortcodes-examples/

Even a red box with no icon, would be a welcome addition. Maybe like this?

http://wordpress.org/plugins/notice-boxes-with-shortcodes/screenshots/

Is it a matter of some quick custom css? Maybe a copy of the css code of “Box Quote Center” but aligned left, and colored red, green, light blue etc?

Thanks so much. Keep up the great work everyone!