Dashboard: recolor the interim omnibar orange in support user sessions

client/dashboard/app/interim-omnibar/index.tsx

@@ -1,3 +1,4 @@
+import { isSupportUserSession } from '@automattic/calypso-support-session';
 // eslint-disable-next-line no-restricted-imports
 import { I18N, I18NContext } from 'i18n-calypso';
 import { hydrateRoot } from 'react-dom/client';
@@ -10,6 +11,12 @@ export default async function loadOmnibar( events: OmnibarEvents ) {
 		return;
 	}
 
+	// Recolor the masterbar for support "user" sessions. "Next" sessions already
+	// have their own indicator, so they're excluded.
+	if ( isSupportUserSession() ) {
+		container.classList.add( 'is-support-user-session' );
+	}
+
 	container.addEventListener( 'click', ( event ) => {
 		if ( event.metaKey || event.ctrlKey || event.shiftKey || event.altKey ) {
 			return;

client/dashboard/app/interim-omnibar/style.scss

@@ -67,3 +67,21 @@ body:has(#wpcom-omnibar) #wpcom {
 		outline: thin dotted;
 	}
 }
+
+// Support "user" session masterbar palette (orange), matching Calypso.
+#wpcom-omnibar.is-support-user-session {
+	--color-masterbar-background: #b26200;
+	--color-masterbar-text: #fff;
+	--color-masterbar-icon: #f3f1f1;
+	--color-masterbar-highlight: #fff;
+	--color-masterbar-border: #8a4d00;
+	--color-masterbar-item-hover-background: #8a4d00;
+	--color-masterbar-item-active-background: #704000;
+	--color-masterbar-unread-dot-background: #3858e9;
+	--color-masterbar-submenu-text: #f3f1f1;
+	// Submenu / site-info backgrounds default to a dark blue-gray from Calypso's
+	// global CSS, which clashes on orange — override them too.
+	--color-sidebar-submenu-background: #704000;
+	--color-masterbar-submenu-group-background: #704000;
+	--color-global-masterbar-site-info-background: #704000;
+}