tailwind.config.js

const {
  default: flattenColorPalette,
} = require("tailwindcss/lib/util/flattenColorPalette");

/** @type {import('tailwindcss').Config} */
module.exports = {
  content: [
    "./src/pages/**/*.{js,ts,jsx,tsx,mdx}",
    "./src/components/**/*.{js,ts,jsx,tsx,mdx}",
    "./src/app/**/*.{js,ts,jsx,tsx,mdx}",
  ],
  theme: {
    extend: {
      backgroundImage: {
        "gradient-radial": "radial-gradient(var(--tw-gradient-stops))",
        "gradient-conic":
          "conic-gradient(from 180deg at 50% 50%, var(--tw-gradient-stops))",
      },
    },
  },
  plugins: [addVariablesForColors],
};

function addVariablesForColors({ addBase, theme }) {
  let allColors = flattenColorPalette(theme("colors"));
  let newVars = Object.fromEntries(
    Object.entries(allColors).map(([key, val]) => [`--${key}`, val])
  );

  addBase({
    ":root": newVars,
  });
}