fix built 2xx.html file

templates/2xx.html

@@ -55,7 +55,6 @@ window.__themeColors = {
   ozark: '#5263af',
   cobalt: '#08439b',
   sorcery: '#ae91e8',
-  gloom: '#fa0000',
   offline: '#999999'
 }
 if (localStorage.store_currentInstance && localStorage.store_instanceThemes) {