Hi there!
Thanks for contacting us.
This doesn't have anything to do with SPPB but with template.
You can try the following code in your custom CSS to change your menu item color for every pages:
#sp-menu .sp-megamenu-parent>li>a {
color: #d95d5d !important;
}
Note: Path towards custom CSS(Joomla 3): Extensions>Templates>Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.
Or, If you want different color for different pages, then you need to duplicate/copy your template style and assign the pages through the menu assignment tab.
https://prnt.sc/pS_mKkGYOxP5
https://prnt.sc/C1or7RMI084l
https://prnt.sc/Oo43ON8TOyLB
Hope this helps!
Best Regards