this is helpful for colors..

modules/user/emacs/default.nix

@@ -41,6 +41,7 @@ in {
           svelte-mode
           typescript-mode
           sass-mode
+          rainbow-mode
           (epkgs.callPackage (
             { lib, fetchurl, trivialBuild }:
             

modules/user/emacs/init.el

@@ -1078,5 +1078,7 @@ Made for `org-tab-first-hook' in evil-mode."
   :init
   (add-hook 'after-init-hook #'scratch-plus-mode))
 
+(use-package rainbow-mode)
+
 (provide 'init)
 ;;; init.el ends here