diff --git a/frontend/src/app/main/data/workspace/colors.cljs b/frontend/src/app/main/data/workspace/colors.cljs
index fba1728d8c..7f21245f49 100644
--- a/frontend/src/app/main/data/workspace/colors.cljs
+++ b/frontend/src/app/main/data/workspace/colors.cljs
@@ -1048,7 +1048,15 @@
           (when-let [color (-> state
                                (select-keys [:image :gradient :color :opacity])
                                (not-empty))]
-            (rx/of (add-recent-color color))))))))
+            ;; Closing the dialog while an image-fill upload is still in
+            ;; flight (or a gradient is mid-edit) leaves the colorpicker
+            ;; with a partial selection — opacity-only, or with stops not
+            ;; yet committed. ``add-recent-color`` runs the value through
+            ;; ``check-color`` and asserts; gate on the same schema here
+            ;; so the partial value is silently dropped instead of crashing
+            ;; the workspace.
+            (when (clr/valid-color? color)
+              (rx/of (add-recent-color color)))))))))
 
 (defn update-colorpicker-gradient
   [changes]
diff --git a/frontend/test/frontend_tests/data/workspace_colors_test.cljs b/frontend/test/frontend_tests/data/workspace_colors_test.cljs
index 947bb6e820..7b2006eb22 100644
--- a/frontend/test/frontend_tests/data/workspace_colors_test.cljs
+++ b/frontend/test/frontend_tests/data/workspace_colors_test.cljs
@@ -46,3 +46,39 @@
                    (ptk/event? (dwc/add-fill #{uuid/zero} color3 1))))
     (t/is (thrown? js/Error
                    (ptk/event? (dwc/add-fill #{uuid/zero} color4 1))))))
+
+
+(t/deftest update-colorpicker-color-skips-add-recent-on-incomplete-image-state
+  ;; Regression for https://github.com/penpot/penpot/issues/8443.
+  ;;
+  ;; Closing the fill dialog while the image upload is still in flight leaves
+  ;; the colorpicker's current-color with only :opacity (no :image, :gradient,
+  ;; or :color). Before the guard, ptk/watch eagerly built (add-recent-color
+  ;; partial), which calls (clr/check-color partial) and threw an "expected
+  ;; valid color" assertion that surfaced as an Internal Assertion Error toast.
+  (let [partial-image-state {:colorpicker {:type :image
+                                           :current-color {:opacity 1}}}
+        event (dwc/update-colorpicker-color {} true)]
+    (t/is (nil? (ptk/watch event partial-image-state nil)))))
+
+
+(t/deftest update-colorpicker-color-skips-add-recent-when-only-opacity-on-color-type
+  ;; Same incomplete-state shape, but the colorpicker is on the plain-color tab
+  ;; (e.g. the user clicked elsewhere before the picker had a chance to commit
+  ;; a hex). The existing :type-and-:color-nil guard sits on the colorpicker
+  ;; map's :type — but get-color-from-colorpicker-state strips :type from its
+  ;; output, so that guard never fires. The schema-based guard catches it.
+  (let [colorless-state {:colorpicker {:type :color
+                                       :current-color {:opacity 1}}}
+        event (dwc/update-colorpicker-color {} true)]
+    (t/is (nil? (ptk/watch event colorless-state nil)))))
+
+
+(t/deftest update-colorpicker-color-still-emits-recent-for-valid-plain-color
+  ;; Sanity check: a fully-populated plain color still produces a watch
+  ;; observable (the rx/of branch is reached) so we know the guard isn't
+  ;; over-eager and silently dropping legitimate colors.
+  (let [valid-state {:colorpicker {:type :color
+                                   :current-color {:color "#ff0000" :opacity 1}}}
+        event (dwc/update-colorpicker-color {} true)]
+    (t/is (some? (ptk/watch event valid-state nil)))))