If you are unable to alter these two colors within the Template Options, the underlying issue may stem from the template.css file. This file also uses an additional class name, which, in the browser, is "stronger" than the override from the Custom Style Preset settings. In that case, please use a simple Custom CSS to set a custom color. In the following example, we used RED, but you can use another (blue, green, yellow, etc.). 

.fixed-menu #sp-header #sp-menu .sp-megamenu-wrapper .sp-megamenu-parent .sp-menu-item.active > a, 
.fixed-menu #sp-header #sp-menu .sp-megamenu-wrapper .sp-megamenu-parent .sp-menu-item:hover > a, 
.fixed-menu #sp-header #sp-menu .sp-megamenu-wrapper .sp-megamenu-parent .sp-menu-item:focus > a, 
.case-studies-page.view-dynamic #sp-header #sp-menu .sp-megamenu-wrapper .sp-megamenu-parent .sp-menu-item.active > a, 
.case-studies-page.view-dynamic #sp-header #sp-menu .sp-megamenu-wrapper .sp-megamenu-parent .sp-menu-item:hover > a,
.case-studies-page.view-dynamic #sp-header #sp-menu .sp-megamenu-wrapper .sp-megamenu-parent .sp-menu-item:focus > a 
{color: red; }