function class doesnt work

To override the default styles you have to use more specific selectors.

#wpadminbar .my_menu_item_class {
    background: yellow;
}  
#wpadminbar .menupop.hover ul li.my_menu_item_class > a {
    color:red;
}

Related Posts:

  1. How to load scripts/styles specific for a page
  2. functions.php inject inline css
  3. How do I create a new WP admin color scheme?
  4. Logout/login redirect CSS issue
  5. Add attribute to link tag that’s generated through wp_register_style?
  6. TinyMCE custom stylesheets for different post types
  7. Remove “says” from comments
  8. How to add CSS style sheet dynamically in wordpress
  9. Simple/basic use of get_current_screen
  10. Is it possible to be more page/post specific with admin_enqueue_script?
  11. Child Theme Not Overriding Parent Theme
  12. CSS stylesheet not loading
  13. Enqueue styles after a plugin
  14. How to add background image control to page admin controls?
  15. Add class or ID to any WordPress function
  16. Register and enqueue style.css custom theme
  17. Multiple CSS body classes to specific page I.D.’s – is this possible?
  18. Enqueue Style Only On Certain Pages Not Working
  19. Why does the ‘wp_nav_menu’ function work only until a menu is created?
  20. Child Theme files – what is needed?
  21. How do I add Bootstrap and LESS to my migrated WordPress site?
  22. How to Display Frontend CSS for Administrator only
  23. WordPress Menuing Question :focus
  24. change the url paths in the stylesheet dynamically
  25. Please Explain the Importing Process of Multiple Stylesheets for Child Themes
  26. Change CSS for logged in users
  27. How to stop wordpress from injecting hard-coded style into image attachments with captions
  28. different style sheet for just one page template
  29. Custom styles.css sheet for visual editor
  30. Is my code correct to enqueue CSS on a specific page?
  31. header_image() with CSS
  32. Not all CSS elements transferring via parent to child?
  33. Split Media Queries in different files!
  34. Some questions about how proper add 2 CSS file in a WordPress theme?
  35. problem loading stylesheets to wp_head dynamically
  36. How to insert class in each list of categories?
  37. Parent theme styles overriding child theme CSS [closed]
  38. I can’t add CSS with functions.php
  39. Theme JS is available but theme CSS isn’t
  40. Proper Way to Load stylesheet on Condition
  41. This code works, but the way I integrated it is breaking the media uploader. How can I integrate it properly?
  42. Default Nav Highlight
  43. Custom styles in Tiny MCE with an external CSS file
  44. why can’t i add front.css to my frontpage.php
  45. get_template_directory_uri() links to child theme not parent
  46. remove/hide wp-editor
  47. Getting out side of wp root folder from function.php using absolute path
  48. Page Template Won’t Load Correct CSS File
  49. current_page_item is missing inside wp_nav_menu
  50. define css class in functions.php
  51. Completely Disable WordPress RSS Feeds
  52. Advanced method to control cache of enqueued style/script
  53. Combine page types and Custom Taxonomy in a functions.php command
  54. Can’t load assets
  55. How to reference different css (bootstrap) stylesheets for the header and body of a page?
  56. Can we have conditional CSS styling?
  57. CSS style and app.js not loading
  58. Post content overflows on my mobile phone
  59. Stylesheet does not load despite functions.php
  60. Remove clickable Link of WordPress Site Logo from Woocommerce Single Product page
  61. How do I make a custom “Read More Blogs” button for my blog page
  62. Help using ShortCodes to style whole chunks of the post
  63. Setting Up Child Theme To Take Priority
  64. how to remove a tag in the_category function
  65. Reference multiple style sheets, clearing styles for permalink page, custom fields for css
  66. CSS disabled after getting rid of emoji
  67. How to add styles in existing function?
  68. Woocommerce – Switching Price for Category
  69. Adding a class to the body of an inactive site using multisite
  70. Conditionally apply css for a specific template part
  71. How do I dequeue a Stylesheet, stored in an ‘Assets’ folder?
  72. Child Theme not loading multiple stylesheets
  73. Correct way of Enqueue self hosted fonts in sass project
  74. Help with is_page() and calling css for specific pages in a Child Theme
  75. Child theme style.css didn’t work properly but the Customize Additional CSS did [closed]
  76. How to automatically add custom classes to headings in content area
  77. Changing the color of post title [closed]
  78. Preventing PHP Execution in Parent Theme
  79. Random text changing to weird icons in both admin & front end
  80. Functions.php in child theme that loads CSS file breaks website
  81. Syling Custom Fields echo’s from from functions.php
  82. functions.php / replacing div’s with new ones?
  83. Should I use `get_stylesheet_uri()` or `get_template_directory_uri()` when calling my CSS Stylesheet?
  84. How can I append and prepend something to all post hyperlinks without using ::before or ::after? PHP hook solution?
  85. Image width issue in IE [closed]
  86. How do I make my child theme’s CSS update when I save it?
  87. Why don’t ‘wp_nav_menu’ CSS classes work until a menu is created?
  88. wp_head not injecting css
  89. Why get_header() or get_footer() does not run twice if called in the same php file?
  90. Best practices regarding the creation of custom widgets?
  91. Multiple Loops Meta Data
  92. What is the text that appears beside the page titles in the list of pages in the WP admin?
  93. dynamic site link for future migration in echo do_shortcode()
  94. Show Featured Image in else statement
  95. Simplest Way to Build Custom Archives Page?
  96. Filter for replacing the WP_query object for a given category
  97. Custom user role still showing up after deletion, ideas?
  98. Search and Replace Script Loader in Head Only Works in Footer
  99. Query is not work
  100. Parse error: syntax error, unexpected ‘endforeach’ (T_ENDFOREACH) in [closed]