Want to use different stylesheets for each of your custom post types? You can use this snippet. Make sure to insert your own custom post type names and your own stylesheet names.

 
function my_editor_style() { 
 
global $current_screen; 
 
switch ($current_screen->post_type) { 
 
case 'post': 
add_editor_style('editor-style-post.css'); 
 
break; 
 
case 'page': 
add_editor_style('editor-style-page.css'); 
 
break; 
 
case 'portfolio': 
add_editor_style('editor-style-portfolio.css'); 
 
break; 
} 
} 
add_action( 'admin_head', 'my_editor_style' );