Random color feature - not working

SassMeister-input-HTML.haml

.col

SassMeister-input.scss

// ----
// Sass (v3.3.0.rc.1)
// Compass (v0.13.alpha.10)
// ----

$red: rgb(random(255), random(255), random(255));

.col {
  background-color: $red;
  width: 100px;
  height: 100px;
  position: absolute;
  left: calc(50% - 100px);
  right: calc(50% - 100px);
}

SassMeister-output.css

.col {
  background-color: #72d646;
  width: 100px;
  height: 100px;
  position: absolute;
  left: calc(50% - 100px);
  right: calc(50% - 100px);
}

SassMeister-rendered.html

<div class='col'></div>