How to put json variable directly into DIV Class

I need to change the color of a div element by a number that I assign in the script section. I am using Nuxtjs and tailwind.

This is the code what I want to work but sadly it doesn't. Anyone knows another way to get to the same result?

<template>
<div class = "bg-[ "{{color}}" ]">
</div>
</template>
<script>
let color = 12345
</script>

So I am wondering is there a way to put a json Variable directly into the div class?