Update Desktop, Obsidian client color theme to lighter yellow

- Update background color to a different shade of white
- Make primary and primary hover colors less intense and more aligned
  with lantern flame shade
- Add water, leaf, flower color variables

src/interface/desktop/chat.html

@@ -303,7 +303,7 @@
         }
         body {
             display: grid;
-            background: #fff;
+            background: var(--background-color);
             color: #475569;
             text-align: center;
             font-family: roboto, karma, segoe ui, sans-serif;