How to make subcategory on side menu to change color?

On my site when you go over “Посребрени Бижута” in the left menu and you get my subcategory. But when you do it the color of the submenu is pink too. Is it possible to make it gray and only when you go to it with the mouse to change the color to pink ?
Thank you,

Hello Boris,

Please try to use the following CSS code.

You can add CSS code in Dashboard → Appearance → Customize → Additional CSS (WordPress 4.7 and up).

.secondary-navigation ul ul.sub-menu {
    background-color: #2C292A;

Please feel free to ask any other questions that you might have.

Kind Regards, Roman.