Why when I Customizing my theme it wont work on the blade?

I'm working on a Laravel project and I'm using Tailwind CSS for it. What I'm trying to do is to add a costume color in order to use it in the class in the HTML just like it is said in the documentation: https://tailwindcss.com/docs/background-color

I have added a color like this:

tailwind.config.js

    theme: {
        extend: {
            fontFamily: {
                sans: ["Nunito", ...defaultTheme.fontFamily.sans],
            },
            colors: {
                emerald: "#2dd4bf",
            },
        },
    },

page.blade.php

<nav class:"bg-emerald">
....
</nav>

The color of the navbar won't change.

How can I fix it?