diff --git a/addons/web_editor/static/src/scss/secondary_variables.scss b/addons/web_editor/static/src/scss/secondary_variables.scss
index 421e6670aa5..1785bb09591 100644
--- a/addons/web_editor/static/src/scss/secondary_variables.scss
+++ b/addons/web_editor/static/src/scss/secondary_variables.scss
@@ -21,7 +21,6 @@ $o-color-palette: map-get($o-color-palettes, $o-color-palette-name) or ();
 // Original color palette can contain override of the default combinations (so keep 'null' values for this merge)
 $o-color-palette: map-merge($-combination-additions, $o-color-palette);
 $o-color-palette: map-merge($o-base-color-palette, $o-color-palette);
-$o-color-palette: o-map-force-nulls($o-color-palette);
 
 // Theme colors
 $o-theme-color-palette: map-get($o-theme-color-palettes, $o-theme-color-palette-name) or () !default;
@@ -43,7 +42,6 @@ $o-theme-color-palette: map-merge((
     'dark': darken(desaturate($-main-color, 80%), min(70%, max(0%, $-main-color-lightness - 10%))), // Does not lower under 10% lightness
 ), $o-theme-color-palette);
 $o-theme-color-palette: map-merge($o-base-theme-color-palette, $o-theme-color-palette);
-$o-theme-color-palette: o-map-force-nulls($o-theme-color-palette);
 
 // Gray colors
 // Extend grays with transparent ones (for some reason, BS4 create black-50 and
@@ -51,7 +49,6 @@ $o-theme-color-palette: o-map-force-nulls($o-theme-color-palette);
 $o-gray-color-palette: map-get($o-gray-color-palettes, $o-gray-color-palette-name) or () !default;
 $o-gray-color-palette: map-merge($o-transparent-grays, $o-gray-color-palette);
 $o-gray-color-palette: map-merge($o-base-gray-color-palette, $o-gray-color-palette);
-$o-gray-color-palette: o-map-force-nulls($o-gray-color-palette);
 
 $o-color-system-initialized: false;
 
diff --git a/addons/web_editor/static/src/scss/web_editor.variables.scss b/addons/web_editor/static/src/scss/web_editor.variables.scss
index 5a0365e1cf9..904dfe72d4d 100644
--- a/addons/web_editor/static/src/scss/web_editor.variables.scss
+++ b/addons/web_editor/static/src/scss/web_editor.variables.scss
@@ -446,21 +446,6 @@ $o-we-sidebar-content-field-toggle-control-shadow: 0 2px 3px 0 $o-we-bg-darkest
 // Edited content
 //------------------------------------------------------------------------------
 
-// Useful to force null values (in website, null values set by the user
-// are removed to act as "removing the user custo and resetting to theme
-// default": ideally, we should review that system to actually removing the
-// custos in that case instead of setting a null value but this cannot be
-// migrated at the moment).
-@function o-map-force-nulls($map) {
-    $-map: ();
-    @each $key, $value in $map {
-        $-map: map-merge($-map, (
-            $key: if($value == 'NULL', null, $value),
-        ));
-    }
-    @return $-map;
-}
-
 $o-support-13-0-color-system: false !default;
 
 $o-checklist-margin-left: 20px;
diff --git a/addons/website/static/src/scss/primary_variables.scss b/addons/website/static/src/scss/primary_variables.scss
index 12c0d432f39..ef0c3a8d00d 100644
--- a/addons/website/static/src/scss/primary_variables.scss
+++ b/addons/website/static/src/scss/primary_variables.scss
@@ -2055,3 +2055,19 @@ $o-theme-font-configs: (
         background-image: $-gradient;
     }
 };
+
+// Replaces 'NULL' string values in a map by the sass null value (this is useful
+// as a "hack" to allow users to define null values in their custom palette as
+// normal null values are immediately removed to act as "removing the user custo
+// and resetting to theme default": ideally, we should review that system to
+// actually removing the custos in those cases instead of setting a null value
+// but this cannot be migrated at the moment).
+@function o-map-force-nulls($map) {
+    $-map: ();
+    @each $key, $value in $map {
+        $-map: map-merge($-map, (
+            $key: if($value == 'NULL', null, $value),
+        ));
+    }
+    @return $-map;
+}
diff --git a/addons/website/static/src/scss/secondary_variables.scss b/addons/website/static/src/scss/secondary_variables.scss
index 14c27077550..cef3c0e5f93 100644
--- a/addons/website/static/src/scss/secondary_variables.scss
+++ b/addons/website/static/src/scss/secondary_variables.scss
@@ -53,9 +53,10 @@ $o-fonts-similar: (
 // By default, most website palette values are null. Each null value is
 // automatically replaced with corresponsing values in chosen default values
 // palette.
+$o-user-website-values: o-map-force-nulls($o-user-website-values);
+$o-user-website-values: o-map-font-aliases($o-user-website-values);
 $-website-values-default: o-safe-nth($o-website-values-palettes, $o-website-values-palette-number, ());
 $-website-values-default: map-merge($o-base-website-values-palette, $-website-values-default);
-$o-user-website-values: o-map-font-aliases($o-user-website-values);
 $-actual-user-website-values-palette: map-merge($-website-values-default, $o-user-website-values);
 // Default font selection + User font selection have been merged, now need to
 // add the right associated font default config
@@ -67,7 +68,7 @@ $o-website-values-palettes: append($o-website-values-palettes, $-actual-user-web
 
 // Enable last website values palette, which is now the user customized one
 $o-website-values-palette-number: length($o-website-values-palettes);
-$o-website-values: o-map-force-nulls($-actual-user-website-values-palette) !default;
+$o-website-values: $-actual-user-website-values-palette !default;
 @function o-website-value($key) {
     @return map-get($o-website-values, $key);
 }
@@ -132,6 +133,7 @@ $o-has-customized-colors:
 // By default, most user color palette values are null. Each null value is
 // automatically replaced with corresponsing colors in chosen default color
 // palette.
+$o-user-color-palette: o-map-force-nulls($o-user-color-palette);
 $-palette-default: map-get($o-color-palettes, $o-color-palette-name) or ();
 $-actual-user-color-palette: map-merge($-palette-default, $o-user-color-palette);
 // Compatibility with old values in old names
@@ -162,6 +164,7 @@ $o-color-palettes: map-merge($o-color-palettes, ('user-palette': $-actual-user-c
 // By default, most user gray palette values are null. Each null value is
 // automatically replaced with corresponsing colors in chosen default color
 // palette.
+$o-user-gray-color-palette: o-map-force-nulls($o-user-gray-color-palette);
 $-palette-default: map-get($o-gray-color-palettes, $o-gray-color-palette-name) or ();
 $-actual-user-gray-color-palette: map-merge($-palette-default, $o-user-gray-color-palette);
 $o-gray-color-palettes: map-merge($o-gray-color-palettes, ('user-palette': $-actual-user-gray-color-palette));
@@ -184,6 +187,7 @@ $-alpha: map-get($o-user-theme-color-palette, 'alpha');
 // By default, all user theme color palette values are null. Each null value is
 // automatically replaced with corresponsing colors in chosen default theme
 // color palette.
+$o-user-theme-color-palette: o-map-force-nulls($o-user-theme-color-palette);
 $-palette-default: map-get($o-theme-color-palettes, $o-theme-color-palette-name) or ();
 $-actual-user-theme-color-palette: map-merge($-palette-default, $o-user-theme-color-palette);
 // Always remove the primary/secondary which were customizable in some theme