make registration background a bit darker

stylesheets/_global.scss

@@ -289,8 +289,6 @@ $loading-height: 16px;
   right: 0;
   top: 0;
   bottom: 0;
-  background-color: white;
-  color: $color-white;
   display: flex;
   align-items: center;
   user-select: none;

stylesheets/_session_left_pane.scss

@@ -378,10 +378,14 @@ $session-compose-margin: 20px;
 }
 
 .app-loading-screen {
-  background: #000;
-
+  @include themify($themes) {
+    background: themed('inboxBackground');
+  }
   .session-text-logo {
-    filter: none !important; // force no filter on the text of the app loading
+    @include themify($themes) {
+      filter: themed('filterSessionText') !important;
+    }
+    // filter: none ; // force no filter on the text of the app loading
     // as the theme is not set right on the start.
     // this is to avoid a text color switch on app loading.
   }

stylesheets/_session_signin.scss

@@ -1,7 +1,7 @@
 .session {
   &-fullscreen {
     @include themify($themes) {
-      background: themed('inboxBackground');
+      background: themed('cellBackground');
     }
     overflow-y: auto;
     height: 100%;
@@ -116,7 +116,7 @@
       margin-left: auto;
       margin-right: auto;
       @include themify($themes) {
-        background: themed('inboxBackground');
+        background: themed('cellBackground');
       }
     }