[Feature]: Tailwind colors

[zmzlois]

Version

System:
    OS: macOS 14.2.1
    CPU: (12) arm64 Apple M2 Pro
    Memory: 82.77 MB / 16.00 GB
    Shell: 5.9 - /bin/zsh
  Browsers:
    Chrome: 125.0.6422.142
    Safari: 17.2.1
  npmPackages:
    rspress: ^1.18.1 => 1.18.1

Details

As title stated

1. tailwind colors don't work until they are explicitly configured in tailwind.config.ts, thought this might be a bug?

2. any documentation on incorporating rspress exposed brand assets to be used with tailwind variables? On tailwind docs (I tried it a couple times hex colors doesn't work at all) it didn't specify how should hex colors be used https://tailwindcss.com/docs/customizing-colors#using-css-variables

Reproduce link

https://github.com/zmzlois/docs/tree/homepage-change

Reproduce Steps

1. Clone the repo
2. Delete color configuration in tailwind.config.ts
3. npm i && npm run dev