<div class="rgb">RGB</div>
<div class="rgba">RGBA</div>
<div class="hsl">HSL</div>
<div class="hsla">HSL</div>
div {
  text-align: center;
  margin: 1rem;
  padding: 1rem;
}

.rgb {
  background-color: rgb(200, 100, 200);  
}

.rgba {
  background-color: rgba(200, 100, 200, .2);  
}

.hsl {
  background-color: hsl(300, 40%, 60%);  
}

.hsla {
  background-color: hsla(300, 40%, 60%, .2);  
}

External CSS

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External JavaScript

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