diff --git a/crates/engine/src/prefs.rs b/crates/engine/src/prefs.rs
index e56867d6..a0d305e9 100644
--- a/crates/engine/src/prefs.rs
+++ b/crates/engine/src/prefs.rs
@@ -262,7 +262,7 @@ fn parse_hex(s: &str) -> Option<[u8; 3]> {
     if h.len() != 6 {
         return None;
     }
-    let p = |i: usize| u8::from_str_radix(&h[i..i + 2], 16).ok();
+    let p = |i: usize| u8::from_str_radix(h.get(i..i + 2)?, 16).ok();
     Some([p(0)?, p(2)?, p(4)?])
 }
 
diff --git a/crates/engine/src/tests_settings.rs b/crates/engine/src/tests_settings.rs
index 8c2fcac5..4afa08fc 100644
--- a/crates/engine/src/tests_settings.rs
+++ b/crates/engine/src/tests_settings.rs
@@ -508,3 +508,16 @@ fn interface_language_is_validated_persisted_and_backward_compatible() {
     assert_eq!(Prefs::from_json(r#"{"general":{"undoLevels":17}}"#).general.language, "en");
     assert_eq!(Prefs::from_json(r#"{"general":{"language":"unknown"}}"#).general.language, "en");
 }
+
+#[test]
+fn unicode_label_colors_fall_back_without_panicking() {
+    use effectcraft_color::Label;
+    let mut s = Session::default();
+    let default = s.prefs.label_rgb(Label::Red);
+    for color in ["#€abc", "#a€bc", "#abc€"] {
+        s.execute("prefs.set", json!({"key": "labels.0.color", "value": color})).unwrap();
+        assert_eq!(s.prefs.label_rgb(Label::Red), default);
+    }
+    s.execute("prefs.set", json!({"key": "labels.0.color", "value": "#aBcD09"})).unwrap();
+    assert_eq!(s.prefs.label_rgb(Label::Red), [0xab, 0xcd, 9]);
+}