Error The text-neutral-900 class does not exist with underscoretw

[zkmark]

I'm trying to use the html version with this wordpress compatible theme (underscoretw)
https://underscoretw.com/

But when you execute any of these 2 commands:
npm run dev
npm run watch

I get this error:

The text-neutral-900 class does not exist. If text-neutral-900 is a custom class, make sure it is defined within a @layer directive.',

I have installed material-tailwind as the documentation says
https://www.material-tailwind.com/docs/html/installation

[sabinolopes]

You can try this: