From fdd08abc0b63b6367e8e130e437eb1b355fdac7b Mon Sep 17 00:00:00 2001
From: Kit Langton <kit.langton@gmail.com>
Date: Mon, 10 Aug 2026 16:41:21 +0000
Subject: [PATCH] fix(tui): support single categorical theme hue

---
 packages/theme/src/tui/syntax.ts          |  2 +-
 packages/tui/test/theme/v2/syntax.test.ts | 12 ++++++++++++
 2 files changed, 13 insertions(+), 1 deletion(-)
 create mode 100644 packages/tui/test/theme/v2/syntax.test.ts

diff --git a/packages/theme/src/tui/syntax.ts b/packages/theme/src/tui/syntax.ts
index d377e67a0380..91acaa7ba746 100644
--- a/packages/theme/src/tui/syntax.ts
+++ b/packages/theme/src/tui/syntax.ts
@@ -12,7 +12,7 @@ export function generateSyntax(theme: ResolvedThemeTokens, mode: Mode) {
     rule(["prompt"], theme.hue.accent[step]),
     rule(["extmark.file"], feedback.warning.default, { bold: true }),
     rule(["extmark.agent"], theme.categorical[0][step], { bold: true }),
-    rule(["extmark.skill"], theme.categorical[1][step], { bold: true }),
+    rule(["extmark.skill"], (theme.categorical[1] ?? theme.categorical[0])[step], { bold: true }),
     // V1 migration preserves its selected/inverse foreground in this action state.
     rule(["extmark.paste"], theme.text.action.primary.focused, {
       background: feedback.warning.default,
diff --git a/packages/tui/test/theme/v2/syntax.test.ts b/packages/tui/test/theme/v2/syntax.test.ts
new file mode 100644
index 000000000000..e7eb03ad411d
--- /dev/null
+++ b/packages/tui/test/theme/v2/syntax.test.ts
@@ -0,0 +1,12 @@
+import { expect, test } from "bun:test"
+import { generateSyntax, resolveThemeDocument } from "@opencode-ai/theme/tui"
+import { SyntaxStyle } from "@opentui/core"
+import { parseTheme } from "../../../src/theme"
+
+test("generates syntax for a single categorical hue", () => {
+  const theme = resolveThemeDocument(parseTheme({ version: 2, light: { categorical: ["red"] } }), "light")
+  const syntax = generateSyntax(theme, "light")
+
+  expect(syntax).toBeInstanceOf(SyntaxStyle)
+  syntax.destroy()
+})