Header menu won't use both active & inactive menu item colors

Hi,

I have a single navigation menu that I’m using for my one page website and it’s in the header area. I’d like for each tab to show as the “inactive menu item” color until you scroll down to each section, where it would then show as the “active menu item” color. For some reason, it’s showing every tab as the “active menu item” color and nothing happens when I hover over a tab or scroll through the page. Would custom CSS fix this or is there something else I need to fix within the menu settings? Thank you.