refactor: improve color modes handling

Author: mrholek

src/App.js

@@ -16,19 +16,20 @@ const Page500 = React.lazy(() => import('./views/pages/page500/Page500'))
 
 const App = () => {
   const { isColorModeSet, setColorMode } = useColorModes('coreui-free-react-admin-template-theme')
-  const theme = useSelector((state) => state.theme)
+  const storedTheme = useSelector((state) => state.theme)
 
   useEffect(() => {
     const urlParams = new URLSearchParams(window.location.href.split('?')[1])
-    if (urlParams.get('theme')) {
-      setColorMode(urlParams.get('theme'))
+    const theme = urlParams.get('theme').match(/^[A-Za-z0-9\s]+/)[0]
+    if (theme) {
+      setColorMode(theme)
     }
 
     if (isColorModeSet()) {
       return
     }
 
-    setColorMode(theme)
+    setColorMode(storedTheme)
   }, []) // eslint-disable-line react-hooks/exhaustive-deps
 
   return (