RGBa-Mixin with fallback for sass.scss

/*
 * RGBa-Mixin with fallback (http://css-tricks.com/rgba-browser-support/)
 */


@mixin transparent-backgound($color: #000, $value:0.5)
  $start: "rgb(";
  $end: ")";
  background: #{$start}red($color), green($color), blue($color)#{$end};
  background: rgba($color, $value);

/*
 * sass
 */
.cnt-matrix .info
  @include transparent-backgound(#f29400, 0.85);

/*
 * output
 */
.cnt-matrix .info {
  background: rgb(242, 148, 0);
  background: rgba(242, 148, 0, 0.85);
}