diff --git a/crates/engine/src/cmd/colormgmt.rs b/crates/engine/src/cmd/colormgmt.rs
index da7dc42ece..9ec21b6541 100644
--- a/crates/engine/src/cmd/colormgmt.rs
+++ b/crates/engine/src/cmd/colormgmt.rs
@@ -274,14 +274,17 @@ fn assign_profile(s: &mut Session, p: &Value) -> Result<Value> {
             Ok(())
         })?;
         let mut st = cms::active_settings();
+        let before = st.clone();
         if let Some(r) = &rgb {
             st.rgb = r.clone();
         }
         if let Some(c) = &cmyk {
             st.cmyk = c.clone();
         }
-        cms::set_active(&st).map_err(|e| bad(C, e.to_string()))?;
-        touch_all(s);
+        if st != before {
+            cms::set_active(&st).map_err(|e| bad(C, e.to_string()))?;
+            touch_all(s);
+        }
     }
     Ok(json!({"rgb": rgb, "cmyk": cmyk}))
 }
diff --git a/crates/engine/src/tests/colormgmt.rs b/crates/engine/src/tests/colormgmt.rs
index d0901f30a0..ae8ac0c4f0 100644
--- a/crates/engine/src/tests/colormgmt.rs
+++ b/crates/engine/src/tests/colormgmt.rs
@@ -308,6 +308,23 @@ fn assign_profile_is_stored_and_undoable() {
     assert_eq!(cmd::colormgmt::doc_profiles(&s.doc().unwrap().doc), (None, None));
 }
 
+/// Assigning the working profiles leaves the active color settings and the other documents'
+/// revisions unchanged.
+#[test]
+fn assigning_the_working_profiles_keeps_the_active_color_settings() {
+    let _g = GLOBAL.lock().unwrap_or_else(|e| e.into_inner());
+    let mut s = session();
+    s.execute("file.new", &json!({"width": 100, "height": 100})).unwrap();
+    let working = cms::active_settings();
+    let active = cms::active();
+    let other = s.documents()[0].revision;
+    let r = s.execute("edit.assignProfile", &json!({"rgb": working.rgb, "cmyk": working.cmyk})).unwrap();
+    assert_eq!((r["rgb"].as_str(), r["cmyk"].as_str()), (Some(working.rgb.as_str()), Some(working.cmyk.as_str())));
+    assert_eq!(cmd::colormgmt::doc_profiles(&s.doc().unwrap().doc), (Some(working.rgb.clone()), Some(working.cmyk.clone())));
+    assert!(std::sync::Arc::ptr_eq(&active, &cms::active()), "the active color settings were replaced");
+    assert_eq!(s.documents()[0].revision, other, "the other document's revision changed");
+}
+
 #[test]
 fn proof_colors_simulate_press_on_screen() {
     let _g = GLOBAL.lock().unwrap_or_else(|e| e.into_inner());
diff --git a/crates/engine/tests/color_settings.rs b/crates/engine/tests/color_settings.rs
index 0cc0edc4d4..c84921f6de 100644
--- a/crates/engine/tests/color_settings.rs
+++ b/crates/engine/tests/color_settings.rs
@@ -57,6 +57,24 @@ fn legacy_profile_name_resolves_in_commands_and_files() {
     cms::set_active(&before).unwrap();
 }
 
+/// Assigning a profile other than the working space replaces the active color settings and raises
+/// the other open documents' revisions.
+#[test]
+fn assigning_another_profile_replaces_the_active_color_settings() {
+    let _g = settings();
+    let mut s = session();
+    exec(&mut s, "file.new", json!({"width": 100, "height": 100}));
+    let before = cms::active_settings();
+    assert_ne!(before.cmyk, cms::DEVICE_CMYK);
+    let active = cms::active();
+    let other = s.documents()[0].revision;
+    exec(&mut s, "edit.assignProfile", json!({"cmyk": cms::DEVICE_CMYK}));
+    assert_eq!(cms::active_settings().cmyk, cms::DEVICE_CMYK);
+    assert!(!std::sync::Arc::ptr_eq(&active, &cms::active()), "the active color settings were not replaced");
+    assert!(s.documents()[0].revision > other, "the other document's revision did not change");
+    cms::set_active(&before).unwrap();
+}
+
 /// Separations Preview follows the Color Settings and the profiles loaded: a renderer draws a gray
 /// square on the Black plate through the new working CMYK profile, and the four process plates
 /// through a proof profile loaded again under the same name, as a new renderer draws them.