JSFiddle - React, Tailwind, and code Playground

HTML

<div class="square"></div>

CSS

.square {
  width: 500px;
  height: 500px;
  background: linear-gradient(red, 10%, transparent, 10%, green, 20%, transparent, 20%, blue, 30%, transparent, 30%, orange, 40%, transparent, 40%, lightblue, 50%, transparent, 50%, purple, 60%, transparent, 60%, pink, 70%, transparent, 70%, lightgreen, 80%, transparent, 80%, brown, 90%, transparent, 90%, yellow);
}