It is disabled by default to not override the user's theme, you might have an error color already in your theme. However, you can add them pretty easily: https://ui3.nuxt.dev/getting-started/theme#colors

Yes, would be nice to have an option for that without manually writing the whole variables for each color and variant (77 in total)

That way, it's easy to switch a colour from the config and have it change everywhere in the app without having to replace each instance of a tailwind colour.

Maybe in the config something like addColorsInTailwind: true

Unfortunately, we can't do that as the @nuxt/ui import can't be dynamic and is hard-coded: https://github.com/nuxt/ui/blob/v3/src/runtime/index.css

Also, Nuxt UI v3 has taken a CSS variable approach to avoid conflicts with the user's theme as mentioned previously, you can simply use the tokens from the color palette: text-(--ui-color-primary-500).

We also have configurable tokens for light and dark mode, for example you can write text-(--ui-primary) which would be the equivalent of text-primary-500 dark:text-primary-400.

Note that you can use the Tailwind CSS colors as usual though.

I understand it can be tedious if you want to use each one of Nuxt UI colors as Tailwind CSS classes but you can make another CSS file and import it. Actually, maybe we can provide another CSS file that does that, something like @import "@nuxt/ui-colors";. I'll think about it!

Would like to go further in the request. Would be much better to have the global classes available in tailwind by default. For exemple i often need for my own component to have the base background / background 2 or base border ect...

Would be great if this can be integrated by default to be consistent accross projects :