diff --git a/data/scripts/o b/data/scripts/o
index dbeeb38..e0f33bc 100755
--- a/data/scripts/o
+++ b/data/scripts/o
@@ -29,6 +29,12 @@
 
 set -euo pipefail
 
+# ── Terminal capability ──────────────────────────────────────────
+USE_COLOR=true
+if [[ "${TERM:-dumb}" == "dumb" ]] || [[ ! -t 1 ]]; then
+    USE_COLOR=false
+fi
+
 # ── Globals set by dispatch ─────────────────────────────────────
 PREFIX=""        # Path prefix based on context
 CTX_SESSION=""   # Session name if in session/agent context
@@ -194,7 +200,11 @@ cmd_prompt() {
     while true; do
         local prompt_str
         if [[ -z "$buf" ]]; then
-            prompt_str=$'\033[1m>\033[0m '
+            if $USE_COLOR; then
+                prompt_str=$'\033[1m>\033[0m '
+            else
+                prompt_str='> '
+            fi
         else
             prompt_str="  "
         fi