Tailwind dynamic classes


While developing this website, I came across a problem where I wanted to change the tag color dynamically based on an array of colors.

const colors = ["red-500", "blue-500", "green-500", "yellow-500", "pink-500"];
technologies.map((technology, idx) => (
  <span class={`bg-${colors[idx % colors.length]} ...`}>{technology}</span>

But, when I checked the preview, I found that the color is not changing even though the class is being added.

TailwindCSS classes not working

This happens because TailwindCSS removes any unused classes by default, i.e., classes that are not explicitly written in your html. So, to fix this, we have two options:

1. Safelist:

TailwindCSS provides a safelist option in the tailwind.config.js file, which allows you to specify the classes that you want to keep when purging unused classes.

module.exports = {
  safelist: [

2. Faster Hack:

Another way to fix this is to add a dummy element to your html, and add the classes to it. This way, TailwindCSS will not remove the classes. Just don't forget to hide the element. You can also write it anywhere in your source code, but I don't prefer this way.

  class="hidden bg-blue-500 bg-green-500 bg-pink-500 bg-red-500 bg-yellow-500"

At the end, I went with the second option, as tailwindCSS advises against using the safelist whenever possible, stating it as a last-resort.

TailwindCSS classes working


Tailwind Content Configuration