[FIX] website: properly mark selected color for menu, footer, etc

When a color combination was used as "color" (base case) for the menu,
the menu background in the boxed template, the footer or the copyright
section, it was not properly marked as selected in the color palette
widget of the editor panel.

Related to task-2599770

closes odoo/odoo#75157

X-original-commit: 04c476a11a084c825725cae89e104e9f205c685b
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/website/static/src/scss/website.scss

@@ -25,7 +25,15 @@ $-seen-urls: ();
 
     // 2) The values in the $theme-colors map are already printed by Bootstrap.
 
-    // 3) The values in the $colors map are also printed by Bootstrap.
+    // 3) The values in the $colors map are also printed by Bootstrap. However,
+    // we have color variables which can contain a reference to a color
+    // combination and that is the info we want in that case.
+    @each $key in ('menu', 'header-boxed', 'footer', 'copyright') {
+        $-value: map-get($o-color-palette, $key);
+        @if type-of($-value) == 'number' {
+            @include print-variable($key, $-value);
+        }
+    }
 
     // 4) The Odoo values map, $o-website-values, must be printed.
     @each $key, $value in $o-website-values {