What happened?

Bug Report: Gemini CLI - Theme Validation Error for text.response key

Summary

The Gemini CLI (v0.38.2) configuration validator identifies the text.response key in a custom theme as an "Unrecognized key(s)" and throws a configuration error. However, the official documentation explicitly lists response as a supported key for theme customization.

Environment

• Gemini CLI Version: 0.38.2
• OS: Darwin (macOS)
• Configuration File: ~/.gemini/settings.json

Steps to Reproduce

1. Define a custom theme in settings.json under ui.customThemes.
2. Within the text object of the custom theme, add a response key with a hex color value.
3. Set ui.theme to the name of this custom theme.
4. Run any gemini command (e.g., gemini --version).

Actual Behavior

The CLI outputs a configuration error:

Invalid configuration in /Users/user2/.gemini/settings.json:

Error in: ui.customThemes.<ThemeName>.text
    Unrecognized key(s) in object: 'response'

Expected Behavior

The CLI should validate successfully, as response is a documented property of the theme text object.

Evidence

1. Documented Schema (from geminicli.com)

The documentation at https://geminicli.com/docs/cli/themes/#changing-themes states:

response: Takes precedence over primary for rendering model responses.

2. User Configuration Example

{
  "ui": {
    "theme": "LimeWhite",
    "customThemes": {
      "LimeWhite": {
        "text": {
          "primary": "#00FF00",
          "response": "#FFFFFF",
          "secondary": "#a0a0a0",
          "accent": "#00FF00"
        }
      }
    }
  }
}

Impact

Users cannot utilize the documented response color override without triggering a validation error on every command execution.

What did you expect to happen?

I expect to not see the configuration warning when i boot up gemini.

The 'response' text colour changes correctly (to white), but gemini still thinks it's configured wrong.

Client information

• CLI Version: 0.38.2
• Git Commit: b0ed611
• Session ID: ce4d364b-58b2-4ccf-9e5b-3fed8277ae87
• Operating System: darwin v24.10.0
• Sandbox Environment: no sandbox
• Model Version: auto-gemini-3
• Auth Type: oauth-personal
• Memory Usage: 86.3 MB
• Terminal Name: Unknown
• Terminal Background: #1e1e1e
• Kitty Keyboard Protocol: Unsupported

Login information

No response

Anything else we need to know?

No response