diff --git a/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx b/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
index d91363954a1..4009b98a4a7 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
@@ -30,6 +30,7 @@ import { Prompt, type PromptRef } from "@tui/component/prompt"
 import type { AssistantMessage, Part, ToolPart, UserMessage, TextPart, ReasoningPart } from "@opencode-ai/sdk/v2"
 import { useLocal } from "@tui/context/local"
 import { Locale } from "@/util/locale"
+import { Color } from "@/util/color"
 import type { Tool } from "@/tool/tool"
 import type { ReadTool } from "@/tool/read"
 import type { WriteTool } from "@/tool/write"
@@ -1298,9 +1299,84 @@ function ReasoningPart(props: { last: boolean; part: ReasoningPart; message: Ass
   )
 }
 
+function findColorCodePositions(text: string): Array<{ start: number; end: number; color: string }> {
+  const result: Array<{ start: number; end: number; color: string }> = []
+  const regex = /#(?:[0-9a-fA-F]{3,4}|[0-9a-fA-F]{6}|[0-9a-fA-F]{8})\b/g
+  let match
+
+  while ((match = regex.exec(text)) !== null) {
+    result.push({
+      start: match.index,
+      end: match.index + match[0].length,
+      color: match[0],
+    })
+  }
+
+  return result
+}
+
+function colorCodePatcher(
+  syntaxStyle: () => ReturnType<ReturnType<typeof useTheme>["syntax"]>,
+  background: () => RGBA,
+) {
+  const patchClient = (client: any) => {
+    if (!client || client._colorPatched) return
+    client._colorPatched = true
+
+    const original = client.highlightOnce.bind(client)
+
+    client.highlightOnce = async (content: string, filetype: string) => {
+      const result = await original(content, filetype)
+      const colors = findColorCodePositions(content)
+
+      if (colors.length > 0 && result.highlights) {
+        result.highlights = result.highlights.filter((h: [number, number, string, any?]) => {
+          const [start, end] = h
+          return !colors.some((pos) => start < pos.end && end > pos.start)
+        })
+
+        const bg = background()
+        for (const pos of colors) {
+          const rgba = Color.hexToRgba(pos.color)
+          const themeBg = {
+            r: Math.round(bg.r * 255),
+            g: Math.round(bg.g * 255),
+            b: Math.round(bg.b * 255),
+          }
+          const blended = Color.blend(rgba, themeBg)
+          const fg = Color.getContrastColor(blended)
+          const name = `color.${pos.color.replace("#", "")}`
+
+          // Always re-register to handle theme changes
+          syntaxStyle().registerStyle(name, {
+            fg: RGBA.fromInts(fg.r, fg.g, fg.b),
+            bg: RGBA.fromInts(blended.r, blended.g, blended.b),
+          })
+
+          result.highlights.push([pos.start, pos.end, name, {}])
+        }
+      }
+
+      return result
+    }
+  }
+
+  const patchAll = (node: any) => {
+    if (!node) return
+    if (node._treeSitterClient) patchClient(node._treeSitterClient)
+    if (typeof node.getChildren === "function") {
+      for (const child of node.getChildren()) patchAll(child)
+    }
+  }
+
+  return patchAll
+}
+
 function TextPart(props: { last: boolean; part: TextPart; message: AssistantMessage }) {
   const ctx = use()
   const { theme, syntax } = useTheme()
+  const patchedColorCodes = colorCodePatcher(syntax, () => theme.background)
+
   return (
     <Show when={props.part.text.trim()}>
       <box id={"text-" + props.part.id} paddingLeft={3} marginTop={1} flexShrink={0}>
@@ -1312,6 +1388,7 @@ function TextPart(props: { last: boolean; part: TextPart; message: AssistantMess
           content={props.part.text.trim()}
           conceal={ctx.conceal()}
           fg={theme.text}
+          ref={patchedColorCodes}
         />
       </box>
     </Show>
diff --git a/packages/opencode/src/util/color.ts b/packages/opencode/src/util/color.ts
index b96deaec478..b2cdcd440a7 100644
--- a/packages/opencode/src/util/color.ts
+++ b/packages/opencode/src/util/color.ts
@@ -4,16 +4,50 @@ export namespace Color {
     return /^#[0-9a-fA-F]{6}$/.test(hex)
   }
 
+  export function hexToRgba(hex: string): { r: number; g: number; b: number; a: number } {
+    const color = hex.replace("#", "")
+    const hasAlpha = color.length === 4 || color.length === 8
+
+    const expanded =
+      color.length <= 4
+        ? color
+            .split("")
+            .map((c) => c + c)
+            .join("")
+        : color
+
+    const r = parseInt(expanded.slice(0, 2), 16)
+    const g = parseInt(expanded.slice(2, 4), 16)
+    const b = parseInt(expanded.slice(4, 6), 16)
+    const a = hasAlpha ? parseInt(expanded.slice(6, 8), 16) / 255 : 1
+
+    return { r, g, b, a }
+  }
+
   export function hexToRgb(hex: string): { r: number; g: number; b: number } {
-    const r = parseInt(hex.slice(1, 3), 16)
-    const g = parseInt(hex.slice(3, 5), 16)
-    const b = parseInt(hex.slice(5, 7), 16)
+    const { r, g, b } = hexToRgba(hex)
     return { r, g, b }
   }
 
+  export function blend(
+    fg: { r: number; g: number; b: number; a: number },
+    bg: { r: number; g: number; b: number },
+  ): { r: number; g: number; b: number } {
+    return {
+      r: Math.round(fg.r * fg.a + bg.r * (1 - fg.a)),
+      g: Math.round(fg.g * fg.a + bg.g * (1 - fg.a)),
+      b: Math.round(fg.b * fg.a + bg.b * (1 - fg.a)),
+    }
+  }
+
   export function hexToAnsiBold(hex?: string): string | undefined {
     if (!isValidHex(hex)) return undefined
     const { r, g, b } = hexToRgb(hex)
     return `\x1b[38;2;${r};${g};${b}m\x1b[1m`
   }
+
+  export function getContrastColor(color: { r: number; g: number; b: number }): { r: number; g: number; b: number } {
+    const luminance = (0.299 * color.r + 0.587 * color.g + 0.114 * color.b) / 255
+    return luminance > 0.5 ? { r: 0, g: 0, b: 0 } : { r: 255, g: 255, b: 255 }
+  }
 }