⚡ Quick Fix (TL;DR)

The Culprit: A CSS color rule applies to an entire element uniformly – there's no way to target a single word inside a heading without first isolating it in its own element.

The Fix: Wrap just the one word in an inline span, then target that span's color independently of the rest of the heading.

<h2>Build your site <span class="highlight-word">faster</span></h2>

.highlight-word {
  color: #0DC0B3;
}