Color of buttons that are active and disabled

Created by: seyfert

I am using a button group as a form input (using data-toggle="buttons"). After the user submits the form, the form is temporarily disabled while the data is being processed. I would expect that while the buttons are disabled it would still be possible to identify which (if any) buttons are selected ('active'). However, the button-variant mixin overrides the color for all states when the button is disabled so every disabled button variant looks the same.

From a usability perspective the current behavior is not ideal because the user may be confused to think that their selections were lost when the form was disabled.

You can see an example of the issue here: http://codepen.io/seyfert/pen/oXqgNN?editors=111 http://codepen.io/seyfert/pen/PqRwXR?editors=101

I think the appropriate fix would be to modify the "disabled" styling in button-variant mixin so only "hover" and "focus" states use the default color for disabled buttons.

See https://github.com/seyfert/bootstrap/commit/11f785060a94f978cd5bdfcbb4064db39143b09d