The emacs cannot define xterm configuration of the background color.
I've debugged the issue down to the point when emacs queries the xterm background color.

Unfortunately, I cannot provide more exact reasons and errors due to a lack of emacs debugging experience.

Details

• Browser and browser version: Electron 17
• OS version: macOS 12.3
• xterm.js version: 4.17.0 and 4.18. Possibly, 4.16.0 affected, too.
• emacs: 26 or 27. Most probably, older versions are affected, too

Steps to reproduce

1. Run the emacs command
2. Observe the current window
3. *scratch* is opened. Expected that the *GNU Emacs* window is opened.