Hi @awake-2,

try this code:

#wpforo #wpforo-wrap #wpforo-menu li a:hover {
     background-color: #a09a9a !important;
}

The CSS codes should be added in the "Custom CSS code" textarea, located in the Dashboard > Forums > Settings > Style Tab.  

Please don't forget to delete all caches and press Ctrl+F5 (twice) on the frontend before checking to reload the updated CSS file.    

Hi Sofy, 

it works but we still have a flicker of the original color.

So finally, I changed all the elements of this color via CSS, then I changed the color in the wpforo styles with the desired color for the menu.

Thank you for your support 🙂