How to highlight one word with colors in html?

Answer 1

You can use <mark> tag.
Ex:
<p> This word is <mark>highlighted</mark> </p>
Use css for custom color.
mark {
background-color: powderblue;
}

Answer 2

You give this on word its own tag and set the color in css
Example:
<p>This is <span style="color: green;">colored</span> Text</p>