gray.scss

@function gray($intensity, $alpha: 1) {
  @return rgba($intensity, $intensity, $intensity, $alpha);
}

/* Thanks Chris Eppstein for simplifying my code! */

/* Testing our new function */
body {
	background: gray(50%);
	background: gray(255, .2);
}

/* Test should output something like: */
body {
  background: #7f7f7f;
  background: rgba(255, 255, 255, 0.2); }