diff --git a/packages/opencode/src/cli/cmd/tui/component/hex-color-preview.tsx b/packages/opencode/src/cli/cmd/tui/component/hex-color-preview.tsx
new file mode 100644
index 00000000000..a1a160c6921
--- /dev/null
+++ b/packages/opencode/src/cli/cmd/tui/component/hex-color-preview.tsx
@@ -0,0 +1,75 @@
+/**
+ * HexColorPreview component that displays colored squares for detected hex codes.
+ * Used alongside markdown content to visualize colors mentioned in text.
+ */
+import { createMemo, For, Show } from "solid-js"
+import { useTheme } from "@tui/context/theme"
+import { RGBA } from "@opentui/core"
+
+// Regex to match hex color codes: #RRGGBB or #RGB
+const HEX_COLOR_REGEX = /#([a-fA-F0-9]{6}|[a-fA-F0-9]{3})\b/g
+
+/**
+ * Converts a 3-character hex to 6-character hex.
+ */
+function expandShortHex(hex: string): string {
+  if (hex.length === 3) {
+    return hex[0] + hex[0] + hex[1] + hex[1] + hex[2] + hex[2]
+  }
+  return hex
+}
+
+/**
+ * Parses a hex color string to RGBA.
+ */
+function hexToRgba(hex: string): RGBA {
+  const expanded = expandShortHex(hex)
+  const r = parseInt(expanded.substring(0, 2), 16)
+  const g = parseInt(expanded.substring(2, 4), 16)
+  const b = parseInt(expanded.substring(4, 6), 16)
+  return RGBA.fromInts(r, g, b)
+}
+
+/**
+ * Determines if foreground should be black (true) or white (false).
+ */
+function shouldUseBlackForeground(color: RGBA): boolean {
+  const luminance = 0.299 * color.r + 0.587 * color.g + 0.114 * color.b
+  return luminance > 0.5
+}
+
+/**
+ * Extracts unique hex color codes from text.
+ */
+function extractHexColors(text: string): string[] {
+  const matches = text.matchAll(HEX_COLOR_REGEX)
+  const unique = new Set<string>()
+  for (const match of matches) {
+    unique.add(match[0].toLowerCase())
+  }
+  return Array.from(unique)
+}
+
+export function HexColorPreview(props: { text: string }) {
+  const { theme } = useTheme()
+
+  const colors = createMemo(() => extractHexColors(props.text))
+
+  return (
+    <Show when={colors().length > 0}>
+      <box flexDirection="row" gap={1} paddingLeft={3} marginTop={1} flexWrap="wrap">
+        <For each={colors()}>
+          {(hex) => {
+            const color = hexToRgba(hex.slice(1))
+            const fg = shouldUseBlackForeground(color) ? RGBA.fromInts(0, 0, 0) : RGBA.fromInts(255, 255, 255)
+            return (
+              <text>
+                <span style={{ bg: color, fg: fg, bold: true }}> {hex} </span>
+              </text>
+            )
+          }}
+        </For>
+      </box>
+    </Show>
+  )
+}
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 aa331ca0f0d..fa0e7df00f5 100644
--- a/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
+++ b/packages/opencode/src/cli/cmd/tui/routes/session/index.tsx
@@ -71,6 +71,7 @@ import { Filesystem } from "@/util/filesystem"
 import { PermissionPrompt } from "./permission"
 import { DialogExportOptions } from "../../ui/dialog-export-options"
 import { formatTranscript } from "../../util/transcript"
+import { HexColorPreview } from "../../component/hex-color-preview"
 
 addDefaultParsers(parsers.parsers)
 
@@ -1303,6 +1304,7 @@ function TextPart(props: { last: boolean; part: TextPart; message: AssistantMess
           conceal={ctx.conceal()}
           fg={theme.text}
         />
+        <HexColorPreview text={props.part.text} />
       </box>
     </Show>
   )