Revise use of gls

- osx layer already chooses gls by preference

- revise use of switches to avoid glitchy colour escapes in dired

private/.spacemacs

@@ -606,13 +606,11 @@ If you are unsure, try setting them in `dotspacemacs/user-config' first."
                                  )
                                 ))
 
-  ;; explicitly set gls for instert-directory-program, to get the
-  ;; formatting switches we want
+  ;; If using osx layer and gls, set the formatting switches we want
   (when (spacemacs/system-is-mac)
     (let ((gls (executable-find "gls")))
       (when gls
-        (setq insert-directory-program gls
-              dired-listing-switches "-aBhl --color --group-directories-first"))))
+        (setq dired-listing-switches "-ahl --group-directories-first"))))
   )
 
 (defun dotspacemacs/user-load ()