Use the following code to change the hover color for the top menu items (by default the hover color is the Primary Color used throughout the site):
#mainnav ul li a:hover {
color: #6f84d2;
}
Tip: replace #6f84d2 with the color you want.
INFO: This is a CSS snippet. If you don’t have a child theme or don’t know how to use one, we recommend that you add this snippet in Customize > Additional CSS.