diff --git a/frontend/src/app/main/data/workspace/colors.cljs b/frontend/src/app/main/data/workspace/colors.cljs
index b78f2c4072..9ce9139871 100644
--- a/frontend/src/app/main/data/workspace/colors.cljs
+++ b/frontend/src/app/main/data/workspace/colors.cljs
@@ -12,7 +12,7 @@
    [app.common.files.helpers :as cfh]
    [app.common.schema :as sm]
    [app.common.text :as txt]
-   [app.common.types.color :as ctc]
+   [app.common.types.color :as types.color]
    [app.common.types.fill :as types.fill]
    [app.common.types.shape :as shp]
    [app.common.types.shape.shadow :refer [check-shadow]]
@@ -181,15 +181,19 @@
   ([ids color position]
    (change-fill ids color position nil))
   ([ids color position options]
-   (ptk/reify ::change-fill
-     ptk/WatchEvent
-     (watch [_ state _]
-       (let [change-fn #(assoc-shape-fill %1 position %2)
-             undo-id   (js/Symbol)]
-         (rx/concat
-          (rx/of (dwu/start-undo-transaction undo-id))
-          (transform-fill state ids color change-fn options)
-          (rx/of (dwu/commit-undo-transaction undo-id))))))))
+   (assert (every? uuid? ids) "expect a coll of uuids for `ids`")
+   (assert (number? position) "expect a number for position")
+
+   (let [color (types.color/check-color color)]
+     (ptk/reify ::change-fill
+       ptk/WatchEvent
+       (watch [_ state _]
+         (let [change-fn #(assoc-shape-fill %1 position %2)
+               undo-id   (js/Symbol)]
+           (rx/concat
+            (rx/of (dwu/start-undo-transaction undo-id))
+            (transform-fill state ids color change-fn options)
+            (rx/of (dwu/commit-undo-transaction undo-id)))))))))
 
 (defn change-fill-and-clear
   ([ids color] (change-fill-and-clear ids color nil))
@@ -208,33 +212,27 @@
   ([ids color] (add-fill ids color nil))
   ([ids color options]
 
-   (assert
-    (ctc/check-color color)
-    "expected a valid color struct")
-
-   (assert
-    (every? uuid? ids)
-    "expected a valid coll of uuid's")
-
-   (ptk/reify ::add-fill
-     ptk/WatchEvent
-     (watch [_ state _]
-       (let [change-fn
-             (fn [shape attrs]
-               (-> shape
-                   (update :fills #(into [attrs] %))))
-             undo-id
-             (js/Symbol)]
-         (rx/concat
-          (rx/of (dwu/start-undo-transaction undo-id))
-          (transform-fill state ids color change-fn options)
-          (rx/of (dwu/commit-undo-transaction undo-id))))))))
+   (assert  (every? uuid? ids) "expected a valid coll of uuid's")
+   (let [color (types.color/check-color color)]
+     (ptk/reify ::add-fill
+       ptk/WatchEvent
+       (watch [_ state _]
+         (let [change-fn
+               (fn [shape attrs]
+                 (-> shape
+                     (update :fills #(into [attrs] %))))
+               undo-id
+               (js/Symbol)]
+           (rx/concat
+            (rx/of (dwu/start-undo-transaction undo-id))
+            (transform-fill state ids color change-fn options)
+            (rx/of (dwu/commit-undo-transaction undo-id)))))))))
 
 (defn remove-fill
   ([ids color position] (remove-fill ids color position nil))
   ([ids color position options]
 
-   (assert (ctc/check-color color)
+   (assert (types.color/check-color color)
            "expected a valid color struct")
    (assert (every? uuid? ids)
            "expected a valid coll of uuid's")
@@ -263,7 +261,7 @@
   ([ids color] (remove-all-fills ids color nil))
   ([ids color options]
 
-   (assert (ctc/check-color color) "expected a valid color struct")
+   (assert (types.color/check-color color) "expected a valid color struct")
    (assert (every? uuid? ids) "expected a valid coll of uuid's")
 
 
@@ -573,11 +571,11 @@
           "expected valid color operations")
 
   (assert
-   (ctc/check-color new-color)
+   (types.color/check-color new-color)
    "expected valid color structure")
 
   (assert
-   (ctc/check-color old-color)
+   (types.color/check-color old-color)
    "expected valid color structure")
 
   (ptk/reify ::change-color-in-selected
@@ -599,7 +597,7 @@
 
 (defn apply-color-from-palette
   [color stroke?]
-  (let [color (ctc/check-color color)]
+  (let [color (types.color/check-color color)]
     (ptk/reify ::apply-color-from-palette
       ptk/WatchEvent
       (watch [_ state _]
@@ -634,7 +632,7 @@
 
 (defn apply-color-from-colorpicker
   [color]
-  (let [color (ctc/check-color color)]
+  (let [color (types.color/check-color color)]
     (ptk/reify ::apply-color-from-colorpicker
       ptk/UpdateEvent
       (update [_ state]
@@ -675,7 +673,7 @@
 
 (defn add-recent-color
   [color]
-  (let [color (ctc/check-color color)]
+  (let [color (types.color/check-color color)]
     (ptk/reify ::add-recent-color
       ptk/UpdateEvent
       (update [_ state]
@@ -695,11 +693,11 @@
 
 (defn apply-color-from-assets
   [file-id color stroke?]
-  (let [color (ctc/check-library-color color)]
+  (let [color (types.color/check-library-color color)]
     (ptk/reify ::apply-color-from-asserts
       ptk/WatchEvent
       (watch [_ _ _]
-        (let [color (ctc/library-color->color color file-id)]
+        (let [color (types.color/library-color->color color file-id)]
           (rx/of (apply-color-from-palette color stroke?)
                  (add-recent-color color)))))))
 
diff --git a/frontend/test/frontend_tests/data/workspace_colors_test.cljs b/frontend/test/frontend_tests/data/workspace_colors_test.cljs
new file mode 100644
index 0000000000..947bb6e820
--- /dev/null
+++ b/frontend/test/frontend_tests/data/workspace_colors_test.cljs
@@ -0,0 +1,48 @@
+;; This Source Code Form is subject to the terms of the Mozilla Public
+;; License, v. 2.0. If a copy of the MPL was not distributed with this
+;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
+;;
+;; Copyright (c) KALEIDOS INC
+
+(ns frontend-tests.data.workspace-colors-test
+  (:require
+   [app.common.uuid :as uuid]
+   [app.main.data.workspace.colors :as dwc]
+   [clojure.test :as t]
+   [potok.v2.core :as ptk]))
+
+(t/deftest build-change-fill-event
+  (let [color1 {:color "#fabada"
+                :opacity 1}
+        color2 {:color "#fabada"
+                :opacity 1
+                :ref-id uuid/zero
+                :ref-file uuid/zero}
+        color3 {:color "#fabada"
+                :opacity -1}
+        color4 {:opacity 1
+                :color "ffffff"}]
+    (t/is (ptk/event? (dwc/change-fill #{uuid/zero} color1 1)))
+    (t/is (ptk/event? (dwc/change-fill #{uuid/zero} color2 1)))
+    (t/is (thrown? js/Error
+                   (ptk/event? (dwc/change-fill #{uuid/zero} color3 1))))
+    (t/is (thrown? js/Error
+                   (ptk/event? (dwc/change-fill #{uuid/zero} color4 1))))))
+
+(t/deftest build-add-fill-event
+  (let [color1 {:color "#fabada"
+                :opacity 1}
+        color2 {:color "#fabada"
+                :opacity 1
+                :ref-id uuid/zero
+                :ref-file uuid/zero}
+        color3 {:color "#fabada"
+                :opacity -1}
+        color4 {:opacity 1
+                :color "ffffff"}]
+    (t/is (ptk/event? (dwc/add-fill #{uuid/zero} color1 1)))
+    (t/is (ptk/event? (dwc/add-fill #{uuid/zero} color2 1)))
+    (t/is (thrown? js/Error
+                   (ptk/event? (dwc/add-fill #{uuid/zero} color3 1))))
+    (t/is (thrown? js/Error
+                   (ptk/event? (dwc/add-fill #{uuid/zero} color4 1))))))
diff --git a/frontend/test/frontend_tests/runner.cljs b/frontend/test/frontend_tests/runner.cljs
index b8bc7c705f..c3def3b7de 100644
--- a/frontend/test/frontend_tests/runner.cljs
+++ b/frontend/test/frontend_tests/runner.cljs
@@ -2,6 +2,7 @@
   (:require
    [cljs.test :as t]
    [frontend-tests.basic-shapes-test]
+   [frontend-tests.data.workspace-colors-test]
    [frontend-tests.helpers-shapes-test]
    [frontend-tests.logic.comp-remove-swap-slots-test]
    [frontend-tests.logic.components-and-tokens]
@@ -39,6 +40,7 @@
    'frontend-tests.util-snap-data-test
    'frontend-tests.util-simple-math-test
    'frontend-tests.basic-shapes-test
+   'frontend-tests.data.workspace-colors-test
    'frontend-tests.tokens.logic.token-actions-test
    'frontend-tests.tokens.logic.token-data-test
    'frontend-tests.tokens.import-export-test