Custom themes are ignored in markdown rendering: inline code uses the built-in dark colors

Version: Claude Code 2.1.288, macOS (Darwin 27.0), Ghostty

Description

With a custom theme active, inline code spans (` foo ) and fenced code blocks without a language are still drawn in the built-in dark theme's permission color (lavender rgb(177,185,249)). The custom theme's permission` override is not used there. Other UI elements (borders, prompt, permission dialogs) use the custom colors correctly.

Steps to reproduce

1. Create ~/.claude/themes/kanagawa-dragon.json:

``json
{
"name": "Kanagawa Dragon",
"base": "dark",
"overrides": { "permission": "#8ba4b0" }
}
``

1. Select it with /theme. It reports Using custom theme "Kanagawa Dragon", and settings.json contains "theme": "custom:kanagawa-dragon".
2. Ask Claude something whose answer includes inline code, e.g. ` --vol 0.35 `.

Expected: Inline code is drawn in #8ba4b0.
Actual: Inline code is drawn in lavender rgb(177,185,249), the built-in dark value.

Likely cause (from the bundled JS)

The markdown renderer colors code spans with:

case "codespan": return On("permission", t)(e.text);

On resolves its theme argument like this:

let i = typeof r === "string" ? oF(r) : r;

oF only recognizes built-in theme names:

function oF(r){switch(r){case"light":…case"light-ansi":…case"dark-ansi":…
  case"light-daltonized":…case"dark-daltonized":…default:return B}}

The theme passed down the markdown path seems to be the name string ("custom:kanagawa-dragon"). It then lands in default and resolves to the built-in dark palette, so neither the custom overrides nor the base field are applied. The same applies to unlabeled fenced code blocks (case "code" → On("permission", t)).

Suggested fix

Pass the resolved theme object (custom overrides merged on top of base) into the markdown renderer, or make oF resolve custom:* names.

Workaround

None that keeps the custom theme. Switching to dark-ansi makes code spans follow the terminal palette, but drops all the custom colors.