post css problem i guess

Environment

"nuxt": "3.17.4",
"@nuxtjs/tailwindcss": "6.13.1",

Reproduction

No response

Describe the bug

Hi, with old version i was able to use like background-color: theme('colors.success.400') !important;

normally i am importing css files in
plugins like this
import '@/assets/css/toast.scss'

but after i upgrade the version

i get error like this

[postcss] /Users/Desktop/assets/css/toast.scss:10:3: 'colors.success.400' does not exist in your theme config. 'colors' has the following keys: 'inherit', 'current', 'transparent', 'black', 'white', 'slate', 'gray', 'zinc', 'neutral', 'stone', 'red', 'orange', 'amber', 'yellow', 'lime', 'green', 'emerald', 'teal', 'cyan', 'sky', 'blue', 'indigo', 'violet', 'purple', 'fuchsia', 'pink', 'rose'

what am i doing wrong normally i have success color in my tailwind file

Additional context

No response

Logs

Start with assets/css/toast.scss and the Tailwind configuration used with Nuxt 3.17.4 and @nuxtjs/tailwindcss 6.13.1; compare the configured success color with the theme('colors.success.400') reference. Done means the stylesheet builds without the reported PostCSS error and the intended color is available.