Hello, @James,
For hover changing the color, you can try with the below-given CSS.
.sidebar-widget ul li a, .widget_product_categories.sidebar-widget ul li:hover a {
color: #dbb867 !important;
}
For Categories Title Text Font Size, please use the below given CSS code and change the value as per your requirements.
h4.widget-title {
font-size: 20px !important;
}
Regards 8Themes Team.